A. 用英语简短介绍美国历史 谁能帮我翻译下，不要用GOOGLE，词霸等翻译工具，谢谢。
17 centuries ago, vast wilderness in North America only Indians and Eskimos live, but after over a hundred years of immigration, this place has become the new home of the peoples of Europe, of which the most important for the establishment of 13 state of the British colony of the 13 states colonies declared independence from the United Kingdom. After a consultation and reform, the federal system, the United States, on the eve of the French Revolution officially on the world stage. The early United States is welcoming foreign immigrants, these immigrants made her grow up fast. The U.S. population, in 1776 only 300 million people, but now more than 200 million. In the process of rapid population growth, the new living space, but also followed and constantly open up, while the direction from east to west extension of the pioneers of Xinjiang is not only engaged in livestock farming, but also to find minerals and other resources. By the 20th century, the United States not only has become a world power, and also in science, technology, medicine and military power of the advanced countries。
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B. 用英文介绍美国历史
Native Americans and European settlers
The indigenous peoples of the U.S. mainland, including Alaska Natives, are believed to have migrated from Asia, beginning between 12,000 and 40,000 years ago.Some, such as the pre-Columbian Mississippian culture, developed advanced agriculture, grand architecture, and state-level societies. After Europeans began settling the Americas, many millions of indigenous Americans died from epidemics of imported diseases such as smallpox.
In 1492, Genoese explorer Christopher Columbus, under contract to the Spanish crown, reached several Caribbean islands, making first contact with the indigenous people. On April 2, 1513, Spanish conquistador Juan Ponce de León landed on what he called "La Florida"—the first documented European arrival on what would become the U.S. mainland. Spanish settlements in the region were followed by ones in the present-day southwestern United States that drew thousands through Mexico. French fur traders established outposts of New France around the Great Lakes; France eventually claimed much of the North American interior, down to the Gulf of Mexico. The first successful English settlements were the Virginia Colony in Jamestown in 1607 and the Pilgrims' Plymouth Colony in 1620. The 1628 chartering of the Massachusetts Bay Colony resulted in a wave of migration; by 1634, New England had been settled by some 10,000 Puritans. Between the late 1610s and the American Revolution, about 50,000 convicts were shipped to Britain's American colonies. Beginning in 1614, the Dutch settled along the lower Hudson River, including New Amsterdam on Manhattan Island.
In 1674, the Dutch ceded their American territory to England; the province of New Netherland was renamed New York. Many new immigrants, especially to the South, were indentured servants—some two-thirds of all Virginia immigrants between 1630 and 1680.By the turn of the 18th century, African slaves were becoming the primary source of bonded labor. With the 1729 division of the Carolinas and the 1732 colonization of Georgia, the thirteen British colonies that would become the United States of America were established. All had local governments with elections open to most free men, with a growing devotion to the ancient rights of Englishmen and a sense of self-government stimulating support for republicanism. All legalized the African slave trade. With high birth rates, low death rates, and steady immigration, the colonial population grew rapidly. The Christian revivalist movement of the 1730s and 1740s known as the Great Awakening fueled interest in both religion and religious liberty. In the French and Indian War, British forces seized Canada from the French, but the francophone population remained politically isolated from the southern colonies. Excluding the Native Americans (popularly known as "American Indians"), who were being displaced, those thirteen colonies had a population of 2.6 million in 1770, about one-third that of Britain; nearly one in five Americans were black slaves. Though subject to British taxation, the American colonials had no representation in the Parliament of Great Britain.
C. 英文介绍关于美国的历史
Native Americans and European settlersThe indigenous peoples of the U.S. mainland, including Alaska Natives, are believed to have migrated from Asia, beginning between 12,000 and 40,000 years ago.Some, such as the pre-Columbian Mississippian culture, developed advanced agriculture, grand architecture, and state-level societies. After Europeans began settling the Americas, many millions of indigenous Americans died from epidemics of imported diseases such as smallpox.In 1492, Genoese explorer Christopher Columbus, under contract to the Spanish crown, reached several Caribbean islands, making first contact with the indigenous people. On April 2, 1513, Spanish conquistador Juan Ponce de León landed on what he called "La Florida"—the first documented European arrival on what would become the U.S. mainland. Spanish settlements in the region were followed by ones in the present-day southwestern United States that drew thousands through Mexico. French fur traders established outposts of New France around the Great Lakes; France eventually claimed much of the North American interior, down to the Gulf of Mexico. The first successful English settlements were the Virginia Colony in Jamestown in 1607 and the Pilgrims' Plymouth Colony in 1620. The 1628 chartering of the Massachusetts Bay Colony resulted in a wave of migration; by 1634, New England had been settled by some 10,000 Puritans. Between the late 1610s and the American Revolution, about 50,000 convicts were shipped to Britain's American colonies. Beginning in 1614, the Dutch settled along the lower Hudson River, including New Amsterdam on Manhattan Island.In 1674, the Dutch ceded their American territory to England; the province of New Netherland was renamed New York. Many new immigrants, especially to the South, were indentured servants—some two-thirds of all Virginia immigrants between 1630 and 1680.By the turn of the 18th century, African slaves were becoming the primary source of bonded labor. With the 1729 division of the Carolinas and the 1732 colonization of Georgia, the thirteen British colonies that would become the United States of America were established. All had local governments with elections open to most free men, with a growing devotion to the ancient rights of Englishmen and a sense of self-government stimulating support for republicanism. All legalized the African slave trade. With high birth rates, low death rates, and steady immigration, the colonial population grew rapidly. The Christian revivalist movement of the 1730s and 1740s known as the Great Awakening fueled interest in both religion and religious liberty. In the French and Indian War, British forces seized Canada from the French, but the francophone population remained politically isolated from the southern colonies. Excluding the Native Americans (popularly known as "American Indians"), who were being displaced, those thirteen colonies had a population of 2.6 million in 1770, about one-third that of Britain; nearly one in five Americans were black slaves. Though subject to British taxation, the American colonials had no representation in the Parliament of Great Britain.
D. 美国历史简介英文版
美国人民是个勇敢而爱好自由的民族. 他们原本来自世界各地, 是许多不同的文化、种族和宗教, 经过长时期的共存结合而形成的, 渐渐他们以身为美国人而自豪.
17世纪以前, 北美广大原野仅有印第安人和爱斯基摩人居住, 但经过百余年的移民, 这里已成为欧洲国家人民的新家园, 而其中最主要为英国人所建立的13州殖民地, 这13州殖民地宣布脱离英国而独立. 几经协商与改革, 联邦体制的美国, 于法国大革命前夕, 正式登上世界舞台. 早期的美国很欢迎外来的移民, 这些移民使她迅速地成长. 美国人口, 在1776 年只有300万人, 而现在则超过2亿. 在人口迅速增加的过程中, 新的生存空间, 也跟着不断开拓, 而方向则由东向西, 拓疆的先驱们不但从事农耕畜牧, 也寻找矿产及其它资源. 到了20世纪,美国不但已成为世界强国, 并且也是科学、技术、医药及军事力量的先进国家.
殖民时期以前(1607以前)
在两万多年前, 有一批来自亚洲的流浪者, 经由北美到中南美洲, 这些人就是印第安人的祖先. 当哥伦布发现新大陆时, 居住在美洲的印第安人, 约有2,000万, 其中有大约100万人住在现在的加拿大和美国中北部, 其余绝大部分住在现在的墨西哥和美国南部. 大约1万年前, 又有另一批亚洲人, 移居到北美北部, 这是后来的爱斯基摩人. 而最早到美洲的白种人大概是维京人, 他们是一群喜好冒险的捕渔人, 有人认为他们在1,000年前,曾到过北美东海岸. 殖民时期(1607～1753) 1607年, 一个约一百人的殖民团体, 在乞沙比克海滩建立了詹姆士镇, 这是英国在北美所建的第一个永久性殖民地. 在以后150年中, 陆续涌来了许多的殖民者, 定居于沿岸地区, 其中大部分来自英国, 也有一部分来自法国、德国、荷兰、爱尔兰和其他国家. 18世纪中叶, 13个英国殖民地逐渐形成, 他们在英国的最高主权下有各自的政府和议会. 这13个殖民区因气候和地理环境的差异, 造成了各地经济形态、政治制度与观念上的差别.
独立运动(1754～1783)
18世纪中叶, 英国在美洲的殖民地与英国之间, 已有了裂痕. 殖民地的扩张, 使他们产生某种自觉, 自觉到英国的迫害, 而萌生独立的念头. 1774年, 来自12州的代表, 聚集在费城, 召开所谓第一次大陆会议, 希望能寻出一条合理的途径, 与英国和平解决问题, 然而英王却坚持殖民地必须无条件臣服于英王, 并接受处分. 1775年, 在麻州点燃战火, 5月, 召开第二次大陆会议, 坚定了战争与独立的决心, 并发表有名的独立宣言, 提出充分的理由来打这场仗, 这也是最后致胜的要素. 1781年, 美军赢得了决定性的胜利, 1783年, 美英签定巴黎条约, 结束了独立战争.
组成新政府(1784～1819)
革命的成功, 使美国人民有了以立法形式表达他们政治观念的机会. 1787年, 在费城举行联邦会议, 会中华盛顿被推为主席, 他们采取一项原则, 即中央的权力是一般性的, 但必须有审慎的规定和说明, 同时, 他们也接受一项事实, 那就是全国性政府必须有税收、铸造货币、调整商业、宣战及缔结条约的权力. 此外, 为了防止中央权力过大, 而采取孟德斯鸠的均权政治学说, 即政府中设置三个平等合作与制衡的部门, 即立法、行 政、司法三种权力相互调和, 制衡而不使任何一权占控制地位.
向西扩张(1820～1849)
19世纪初期, 数以千计的人, 越过阿帕拉契山, 向西移动, 有些开拓者, 移居到美国的边界, 甚至深入属于墨西哥的领地、以及介于阿拉斯加与加利福尼亚的俄勒冈. 开拓者勇敢、勤奋地向西寻求更好的生活.
南北冲突(1850～1869)
引起内战的原因, 不单是经济上、政治上、军事上的问题, 还包括了思想上的冲突. 内战暴露了美国的弱点. 对这个国家的存在, 作了一番考验. 经过了这次考验, 美国才步向一个中央集权化之现代国家的坦途. 南北之间, 为奴隶问题而起争执, 南方在全国政治上的主要方针, 就在保护和扩大"棉花与奴隶"制度所代表的利益；而北部各州, 主要是制造业、商业和 金融的中心, 这些生产无需依赖奴隶, 这种经济上和政治上的冲突都是由来已久的. 1860年代初期, 11个南方的州脱离联邦, 另组政府, 北方则表示, 为了统一将不惜付出任何代价. 1861年, 内战爆发了, 这场美国人面对面的流血战, 打了四年, 南方遭到严重的破坏, 而且留下深深的伤痕. 1865年, 北方战胜了, 这项胜利不但显示美国回复统一, 而且, 从此全国各地不再施行奴隶制度.
工业化与改革(1870～1916)
19世纪初期, 美国开始工业化, 而内战之后, 则步入成熟阶段. 在从内战至第一次世界大战的不到50年时间内, 她从一个农村化的共和国变成了城市化的国家. 机器代替了手工,产品大量增加. 全国性的铁道网, 增进了货品流通. 应大众的需要, 许多新发明应市了. 银行业提供贷款, 促成工商业经营的扩大. 故从1890到1917年的近30年间被称为所谓"进步时期", 1914 年, 世界大战爆发, 1917年,美国终于被卷入大战漩涡中, 并且在世界上尝试扮演新的角色.
世界的新地位(1917～1929)
在战后的10年间, 美国的社会与文化可说是个无生气、无感情, 属于商人阶级的10年. 据1929年统计, 居城 与居乡的比率是56%∶44%, 这时举凡现代生活的特色, 诸如汽车、电话、收音机、洗衣机, 已成为生活的必需品. 战后经济呈现极度的繁荣, 原因有二, 一为政府不再干涉私营企业且有立法保护之, 二为新技术的带 动. 虽然经济成长很快, 但是基础不稳.
不景气时代和第二次世界大战(1930～1959)
经济大恐慌, 影响的不只是美国, 世界各国都受到它的打击, 经济大恐慌, 使上百万的工人失业, 大批的农人被迫放弃耕地, 工厂商店关门, 银行倒闭…… 一片萧条. 1932年, 罗斯福当选总统, 他主张政府应拿出行动来结束经济大恐慌, 新政府虽然解决了许多的困难, 但美国的经济还是要到二次大战, 才苏醒起来. 第二次世界大战之后, 美苏两国, 关系日趋恶化, 分别在军事、政治、经济、宣传各方面, 加紧准备, 一如战时, 这种状态, 被称为"冷战".
1960年以来
美国历史自1960以来, 许多方面仍是战后发展的延续. 经济方面, 除了周期性的不景气, 则仍不断膨胀；从 城市移居到郊区的人口, 继续增加, 1970年, 居郊人口超过了居城人口. 1960年初期, 黑人问题成为美国内部最主要的问题.
1960年代中期, 许多美国人开始不满政府的对外政策. 此外, 由于工业的发展, 人口的集中, 60年代后期, 生态环境的污染广受注意. 70年代初期, 由于能源危机而导致的经济萧条, 是大恐慌以来, 最严重的一次.
70年代中期, 经济一度复苏, 但到70年代未期, 又出现通货膨胀. 1976年, 美国建国200周年, 全国举行各项庆祝活动. 1981年4月12日, 美国成功地发射"哥伦比亚号"航天飞机, 将人类又带入另一个太空新纪元. 1985年, 里根连任总统, 在日新月异的人类发展史中,美国将展开新的一页.
E. 谁能写美国历史简介(英文版)
The United States of America is a country of the western hemisphere, comprising fifty states and several territories. Forty-eight contiguous states lie in central North America between the Pacific and Atlantic Oceans, bound on land by Canada to the north and Mexico to the south; Alaska is in the northwest of the continent with Canada to its east, and Hawaii is in the mid-Pacific. The United States is a federal constitutional republic; Washington, its capital, is coextensive with the District of Columbia (D.C.), the federal capital district.
At over 3.7 million square miles (over 9.6 million km�0�5) and with over 300 million people, the United States is the third or fourth largest country by total area and third largest by population. With a gross domestic proct (GDP) of over $13 trillion, the U.S. has the largest national economy in the world. GDP per capita ranks first among the larger economies of the world, and third or eighth overall, depending on the measurement. The proct of large-scale historical immigration and home to a complex social structure as well as a wide array of household arrangements,[7] the U.S. is one of the world's most ethnically and socially diverse nations.
The nation was founded by thirteen colonies declaring their independence from Great Britain on July 4, 1776 as the new nation, the "United States of America." It adopted the current constitution (which has been amended several times subsequently) on September 17, 1787. The country greatly expanded in territory throughout the 19th century, acquiring further territory from Great Britain, as well as lands from France, Mexico, Spain, and Russia. With the collapse of the Soviet Union in 1991, it became the world's sole remaining superpower, and is a declared nuclear weapons state. The United States continues to exert dominant economic, political, cultural and military influence around the globe.
美利坚合众国（英语：United States of America），通称美国，旧称花旗国，是位于北美洲的联邦共和制国家，也是世界上最为悠久的共和立宪制国家。
美国本土东濒大西洋，西临太平洋，北靠加拿大，南接墨西哥及墨西哥湾。首都为华盛顿哥伦比亚特区。
美国源自于1776年脱离英国统治的北美殖民地，13州的殖民地代表一同发表了《美国独立宣言》，在经历艰苦的独立战争后，于1783年与英国签订了巴黎协约，从此受到世界各国的承认。
经过两百多年的发展，美国国土不断拓展，37个州陆续加入联邦旗下。目前有50个州，1个联邦直辖特区，以及若干海外领地。国土面积超过962万平方公里，是世界上第三国土面积的国家。美国有3亿居民，人口数量位居世界第三。美国国旗上的50颗白色星星代表50个州；每当新州加入联邦，次年的7月4日国旗将增加一颗星。国旗上红色及白色横条各7及6条，共13条，纪念最初的13个州。
建国200多年以来，美国曾经历过内战（1861—65年）和经济大恐慌（1930年代）两次严酷考验，仍坚守自由民主制政治制度，成为宪法民主和公民自由的代表性国家。美国庞大的经济、文化、科技、和军事影响力贯穿了整个20世纪。在第一次世界大战和第二次世界大战中，美国和同盟国一同获得胜利，并经历数十年的冷战后终于拖垮苏联，成为世界上唯一的超级大国[5]。当今美国在全世界的经济、政治、军事等众多领域的庞大影响力都是无他国能比的。
F. 我想要一个关于美国发展历史的英文介绍，谢谢了，最好要中英对照！急啊！多谢！！
美国 [United States]正式名称美利坚合众国。
北美洲联邦共和国。领土包括美洲大陆中纬度地区48个连成一片的州、北美洲西北端的阿拉斯加州，以及太平洋中部的岛州夏威夷。面积：(包括五大湖)9,529,063平方千米。人口：约286,067,000(2001)。首都：华盛顿特区。人口包括白人、非洲裔美国人、西班牙裔美国人、亚洲人、太平洋岛民、美洲印第安人(美洲土着)、爱斯基摩人及阿留申人。语言：英语(主要语言)、西班牙语。宗教：新教、天主教、犹太教和伊斯兰教。货币：美元。地形由山脉、平原、低地和沙漠构成。山脉包括阿巴拉契亚山脉、欧扎克山、落基山脉、喀斯喀特山脉和内华达山脉。最低点是加利福尼亚州的死谷。最高点是阿拉斯加山脉的麦金利山，而在美国本土，最高点则是惠特尼山。主要河流是密西西比河系、科罗拉多河、哥伦比亚河和格兰德河。五大湖、大盐湖和奥基乔比湖为几个最大的湖。美国是世界某些矿产的主要生产国，包括铜、银、锌、金、煤、石油和天然气；也是食品的主要输出国。制造业包括钢铁产品、化学制品、电子产品和纺织品。其他重要行业为旅游业、奶制品业、畜牧业、渔业和木材加工业。美国是两院制共和国。总统为国家元首和政府首脑。数千年以前已有一些美洲印第安人定居在这块领土，他们可能是来自亚洲。16世纪欧洲人来此探险和定居，开始取代印第安人。第一个欧洲人永久居民点是由西班牙人于1565年在佛罗里达州建立的圣奥古斯丁，后来英国人在弗吉尼亚州詹姆斯敦(1607)、马萨诸塞州普里茅斯(1620)、马里兰州(1634)和宾夕法尼亚州(1681)建立定居点。在卡罗来纳被授予英国贵族一年后，1664年英国人从荷兰人手中夺走纽约、新泽西和德拉瓦。英国人于1763年击败法国人(参阅法英北美殖民地争夺战[French and Indian War])，在政治上控制了13个殖民地。英国殖民政策引起的政治动乱，以美国独立战争(1775～1783)和《独立宣言》(1776)而告结束。美国在《邦联条例》(1781)下首次组织起来，终于通过宪法(1787)成为联邦共和国。随后确认了西至密西西比河的美国疆界，但并不包括西班牙的属地佛罗里达。通过1803年的路易斯安那购地，美国从法国人手中购得的土地使美国领土几乎增加一倍。美国在1812年战争中与英国开战，1819年从西班牙人手中夺得佛罗里达。1830年通过立法手段将美洲印第安人迁移到密西西比河以西的土地。19世纪中叶开始向西部扩张，特别是1848年在加利福尼亚州发现金矿以后(参阅淘金热[gold rush])。美国在墨西哥战争(1846～1848)中取得的胜利，使后来的7个州(包括加利福尼亚和得克萨斯)的部分或全部领土并入美国。1846年美国与英国签订条约确立其西北部疆界，在1853年加兹登购地中又获得亚利桑那州南部的土地。后来南方蓄奴的种植园经济和北方自由的工业与农业经济之间存在的矛盾冲突使美国分裂，爆发了南北战争(1861～1865，参阅美国南北战争[American Civil War])。第十三条宪法修正案废除了奴隶制。重建时期(1865～1877)以后，美国经历了快速发展、都市化、工业开发和欧洲移民。1877年美国准许把印第安人保留地的土地分给个别部落成员，致使大片土地落入白人手中。到19世纪末，美国的外贸得到发展并获得海外领土，包括阿拉斯加、中途岛、夏威夷群岛、菲律宾群岛、波多黎各、关岛、威克岛、美属萨摩亚、巴拿马运河区和维尔京群岛。1917～1918年美国参加了第一次世界大战。1920年给予妇女选举权；1924年给予美洲印第安人公民权。1929年的股市崩溃导致大萧条。日本人偷袭珍珠港(1941-12-07)之后美国加入第二次世界大战。美国在日本广岛投下第一颗原子弹(1945-08-06)，在长崎投下第二颗原子弹(1945-08-09)，导致这场战争结束，并使美国成为西方世界的领袖。美国参与了欧洲和日本的战后重建工作，但却陷入与苏联长达40年的冷战对抗。美国参加了朝鲜战争。1952年给予波多黎各自治地位。1954年宣布在美国学校中实行的种族隔离违反了美国宪法。1959年阿拉斯加和夏威夷成为美国的两个州。1964年国会通过《民权法》，并授权全面干预越南战争。20世纪60年代中至末期美国国内各地发生骚乱，包括种族暴乱和反战示威。1969年美国完成首次人类登陆月球。1973年美军全部撤出越南。在波斯湾战争(1991)中，美国领导联军攻打伊拉克。1992年派兵到索马里救援饥民。1995年和1999年加入北大西洋公约组织空袭前南斯拉夫的塞尔维亚军队。1998年W.J.克林顿总统成为第二个要被美国众议院弹劾的总统；1999年他被参议院宣布无罪。1999年巴拿马运河的管理移交给了巴拿马。2000年G.W.布什成为1888年以来尽管获得的选票略低于对手A.戈尔，但仍被总统选举团选为总统的第一人。2001年9月11日恐怖分子的攻击摧毁了世界贸易中心和五角大楼的部分建筑以后，美国以藏匿并拒绝引渡此次恐怖活动的策划嫌疑本·拉登为由，派兵向阿富汗的塔利班政府发动进攻。
United States
officially United States of America
Federal republic, North America.
It comprises 48 contiguous states occupying the mid-continent, Alaska at the northwestern extreme of North America, and the island state of Hawaii in the mid-Pacific Ocean. Area, including the U.S. share of the Great Lakes: 3,675,031 sq mi (9,518,287 sq km). Population (2002 est.): 287,602,000. Capital: Washington, D.C. The population includes people of European and Middle Eastern ancestry, African Americans, Hispanics, Asians, Pacific Islanders, American Indians (Native Americans), and Alaska Natives. Languages: English (predominant), Spanish. Religions: Protestantism, Roman Catholicism, Judaism, Islam. Currency: U.S. dollar. The country's regions encompass mountains, plains, lowlands, and deserts. Mountain ranges include the Appalachians, Ozarks, Rockies, Cascades, and Sierra Nevada. The lowest point is Death Valley, Calif. The highest point is Alaska's Mount McKinley; within the coterminous U.S. it is Mount Whitney, Calif. Chief rivers are the Mississippi system, the Colorado, the Columbia, and the Rio Grande. The Great Lakes, the Great Salt Lake, and Lake Okeechobee are the largest lakes. The U.S. is among the world's leading procers of several minerals, including copper, silver, zinc, gold, coal, petroleum, and natural gas; it is the chief exporter of food. Its manufactures include iron and steel, chemicals, electronic equipment, and textiles. Other important instries are tourism, dairying, livestock raising, fishing, and lumbering. The U.S. is a republic with two legislative houses; its head of state and government is the president. The territory was originally inhabited for several thousand years by numerous American Indian peoples who had probably emigrated from Asia. European exploration and settlement from the 16th century began displacement of the Indians. The first permanent European settlement, by the Spanish, was at Saint Augustine, Fla., in 1565; the British settled Jamestown, Va. (1607); Plymouth, Mass. (1620); Maryland (1634); and Pennsylvania (1681). The British took New York, New Jersey, and Delaware from the Dutch in 1664, a year after the Carolinas had been granted to British noblemen. The British defeat of the French in 1763 (see French and Indian War) assured British political control over its 13 colonies. Political unrest caused by British colonial policy culminated in the American Revolution (1775–83) and the Declaration of Independence (1776). The U.S. was first organized under the Articles of Confederation (1781), then finally under the Constitution (1787) as a federal republic. Boundaries extended west to the Mississippi River, excluding Spanish Florida. Land acquired from France by the Louisiana Purchase (1803) nearly doubled the country's territory. The U.S. fought the War of 1812 against the British and acquired Florida from Spain in 1819. In 1830 it legalized removal of American Indians to lands west of the Mississippi River. Settlement expanded into the Far West in the mid-19th century, especially after the discovery of gold in California in 1848 (see gold rush). Victory in the Mexican War (1846–48) brought the territory of seven more future states (including California and Texas) into U.S. hands. The northwestern boundary was established by treaty with Great Britain in 1846. The U.S. acquired southern Arizona by the Gadsden Purchase (1853). It suffered disunity ring the conflict between the slavery-based plantation economy in the South and the free instrial and agricultural economy in the North, culminating in the American Civil War and the abolition of slavery under the 13th Amendment. After Reconstruction (1865–77) the U.S. experienced rapid growth, urbanization, instrial development, and European immigration. In 1877 it authorized allotment of American Indian reservation land to indivial tribesmen, resulting in widespread loss of land to whites. By the end of the 19th century, it had developed foreign trade and acquired outlying territories, including Alaska, Midway Island, the Hawaiian Islands, the Philippines, Puerto Rico, Guam, Wake Island, American Samoa, the Panama Canal Zone, and the Virgin Islands. The U.S. participated in World War I in 1917–18. It granted suffrage to women in 1920 and citizenship to American Indians in 1924. The stock market crash of 1929 led to the Great Depression. The U.S. entered World War II after the Japanese bombing of Pearl Harbor (Dec. 7, 1941). The explosion by the U.S. of an atomic bomb on Hiroshima (Aug. 6, 1945) and another on Nagasaki (Aug. 9, 1945), Japan, brought about Japan's surrender. Thereafter the U.S. was the military and economic leader of the Western world. In the first decade after the war, it aided the reconstruction of Europe and Japan and became embroiled in a rivalry with the Soviet Union known as the Cold War. It participated in the Korean War from 1950 to 1953. In 1952 it granted autonomous commonwealth status to Puerto Rico. Racial segregation in schools was declared unconstitutional in 1954. Alaska and Hawaii were made states in 1959. In 1964 Congress passed the Civil Rights Act and authorized U.S. entry into the Vietnam War. The mid-to late 1960s were marked by widespread civil disorder, including race riots and antiwar demonstrations. The U.S. accomplished the first manned lunar landing in 1969. All U.S. troops were withdrawn from Vietnam in 1973. The U.S. led a coalition of forces against Iraq in the First Persian Gulf War (1991), sent troops to Somalia (1992) to aid starving populations, and participated in NATO air strikes against Serbian forces in the former Yugoslavia in 1995 and 1999. In 1998 Pres. Bill Clinton became only the second president to be impeached by the House of Representatives; he was acquitted by the Senate in 1999. Administration of the Panama Canal was turned over to Panama in 1999. In 2000 George W. Bush became the first person since 1888 to be elected president by the electoral college despite having won fewer popular votes than his opponent, Al Gore. After the September 11 attacks on the U.S. in 2001 destroyed the World Trade Center and part of the Pentagon, the U.S. attacked Afghanistan's Taliban government for harbouring and refusing to extradite the mastermind of the terrorism, Osama bin Laden.