AmericaHD1

The United States of America (also referred to as the United States, the U.S., the USA, the States, or America) is a federal constitutional republic comprising fifty states and a federal district. The country is situated mostly in central North America, where its forty-eight contiguous states and Washington, D.C., the capital district, lie between the Pacific and Atlantic Oceans, bordered by Canada to the north and Mexico to the south. The state of Alaska is in the northwest of the continent, with Canada to the east and Russia to the west across the Bering Strait. The state of Hawaii is an archipelago in the mid-Pacific. The country also possesses several territories in the Caribbean  and Pacific.

美國的國土面積是世界第三或者第四大，僅次於俄羅斯、加拿大，在中國之前或之後。排名不同取決於中印兩國領土爭議，以及美國領土總面積的計算方法。美國國家審計局記載9,629,091平方公里，美國中央情報局出版的《世界概況》記載美國國土面積為9,826,630平方公里，[54]不列顛百科全書則記載9,522,055平方公里。[55]如果只計陸地區域，美國排名第三，僅次於俄羅斯、中國，在加拿大之前[56]。美國也擁有許多散佈於加勒比海（例如波多黎各）與太平洋（例如關島）上的海外領土。美國國土東至大西洋、西至太平洋、南至墨西哥灣、北至加拿大。阿拉斯加州也與加拿大接壤，南至太平洋而北至北冰洋。夏威夷州則處在太平洋的群島上，位於北美大陸的西南方。