美国经济历史英文论文格式

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 (.), the federal capital district. At over million square miles (over 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 product (GDP) of over $13 trillion, the . 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 product of large-scale historical immigration and home to a complex social structure as well as a wide array of household arrangements,[7] the . 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。