美国城市化

美国城市化进程贯穿其整个历史进程。在过去的两个世纪里，美利坚合众国已从以农村、农业为主的国家转变为城市化、工业化国家。这很大程度上要归功于18世纪末和19世纪初美国（以及部分西欧国家）的工业革命，以及美国由此经历的快速工业化。1790年，美国人住在城市的只有1/20，但这个比例在1870年急剧变化，到1920年变成了1/4，到20世纪60年代变成了2/3，到21世纪头十年变成了4/5。

美国普查局在1950年和1990年修改了城市地区（Urban Areas, UAs）的分类和定义，因此在比较不同时期的城市数据时需要谨慎。人口普查局目前（2018年）对城市地区的定义是：人口超过5万的连续建成区；包括一个或多个中心地区和城市边缘——由邻近的其他地方和非地方领土组成、密集居住的周边地区。

概况
美国的城市化经历了很长一段时间，直到1910年至1920年之间美国才达到城市人口占多数的地位。目前，超过五分之四的美国人口居住在城市地区，这个比例目前仍在上升。

美国东北部城市化速度最快，到1880年，东北部城市人口已占多数。在此之前，美国东北部的一些州城市人口已经占多数，包括马萨诸塞州和罗德岛州（1850年城市人口占多数），以及纽约州（1870年以来城市人口占多数）。美国中西部和西部在20世纪10年代城市人口成为主体，而美国南部直到第二次世界大战后，也就是20世纪50年代城市人口才成为主体。

今天，美国西部是美国城市化程度最高的地区，紧随其后的是美国东北部。第二次世界大战后，美国南部经历了快速的工业化，现在超过四分之三的人口都生活在城市，2010年南部的城市人口比例几乎与美国中西部相同。如今，美国50个州中只有4个州的农村人口占多数，甚至其中一些州（如密西西比州）仍在继续城市化。目前，美国一些州的城市化率在90%左右或以上，一个世纪以前几乎没有任何一个州能有这样的城市化率。

缅因州和佛蒙特州却在去城市化，这种去城市化趋势在美国其他地方都有体现。缅因州城市人口比例最高的时期是在1950年，当时城市化率还不到52%，而如今，该州只有不到39%的人口居住在城市地区。缅因州目前是美国城市化程度最低的州，它的城市人口比例（39%）还不到美国平均水平（81%）的一半。自1790年第一次人口普查以来，缅因州的城市化程度一直都低于美国平均水平。

历史数据
本表部分数据来自美国人口普查局。注意，城市人口的定义随着时间的推移而变化。1900年、1950年和2000年的人口普查采用了新的定义。
 按美国领地和州划分的城市人口占总人口的百分比（1790-2010） 州/领地2020 2010 2000 1990 1980 1970 1960 1950 1940 1930 1920 1910 1900 1890 1880 1870 1860 1850 1840 1830 1820 1810 1800 1790  80.0% 80.7% 79.0% 78.0% 73.7% 73.6% 69.9% 64.0% 56.5% 56.1% 51.2% 45.6% 39.6% 35.1% 28.2% 25.7% 19.8% 15.4% 10.8% 8.8% 7.2% 7.3% 6.1% 5.1% 美國東北部 84.0% 85.0% 84.4% 84.0% 79.2% 80.5% 80.2% 79.5% 76.6% 77.6% 75.5% 71.8% 66.1% 59.0% 50.8% 44.3% 35.7% 26.9% 18.5% 14.2% 11.0% 10.9% 9.3% 8.1% 美國中西部 74.3% 75.9% 74.7% 73.9% 70.5% 71.6% 68.7% 64.1% 58.4% 57.9% 52.3% 45.1% 38.6% 33.1% 24.2% 20.8% 13.9% 9.2% 3.9% 2.6% 1.1% 0.9% 0.0%  美国南部 75.8% 75.8% 72.8% 71.5% 66.9% 64.8% 58.5% 48.6% 36.7% 34.1% 28.1% 25.5% 18.3% 16.3% 12.2% 12.2% 9.6% 8.3% 6.7% 5.3% 4.6% 4.1% 3.0% 2.1% 美國西部 88.9% 89.8% 88.6% 87.6% 83.9% 83.0% 77.7% 69.5% 58.5% 58.4% 51.8% 47.9% 39.9% 37.0% 30.2% 25.8% 16.0% 6.4%       57.7% 59.0% 55.4% 56.8% 60.0% 58.6% 54.8% 43.8% 30.2% 28.1% 21.7% 17.3% 11.9% 10.1% 5.4% 6.3% 5.1% 4.6% 2.1% 1.0% 0.0% 0.0% 0.0%  64.9% 66.0% 65.6% 61.0% 64.3% 56.9% 37.9% 26.6% 24.0% 13.2% 5.6% 9.5% 24.5% 0.0% 0.0%          89.3% 89.8% 88.2% 86.5% 83.8% 79.6% 74.5% 55.5% 34.8% 34.4% 36.1% 31.0% 15.9% 9.4% 17.3% 33.4% 0.0%        55.5% 56.2% 52.5% 52.0% 51.6% 50.0% 42.8% 33.0% 22.2% 20.6% 16.6% 12.9% 8.5% 6.5% 4.6% 2.6% 0.9% 0.0% 0.0% 0.0% 0.0% 0.0%   94.2% 95.0% 94.4% 93.7% 91.3% 90.9% 86.4% 80.7% 71.0% 73.3% 67.9% 61.8% 52.3% 48.6% 42.9% 37.2% 20.7% 7.4%       86% 86.2% 84.5% 83.8% 80.6% 78.5% 73.7% 62.7% 52.6% 50.2% 48.2% 50.3% 48.3% 45.0% 31.4% 11.9% 13.9%        86.3% 88.0% 87.7% 87.0% 78.8% 78.4% 78.3% 77.6% 67.8% 70.4% 67.8% 65.6% 59.9% 50.9% 41.9% 33.0% 26.5% 16.0% 12.6% 9.4% 7.6% 6.1% 5.1% 3.0% 82.6% 83.3% 80.1% 79.2% 70.6% 72.2% 65.6% 62.6% 52.3% 51.7% 54.2% 48.0% 46.4% 42.2% 33.4% 24.7% 18.9% 15.3% 10.7% 0.0% 0.0% 0.0% 0.0% 1.3% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 90.0% 91.6% 93.0% 93.6% 90.9% 90.1% 88.3% 85.0% 76.2%  91.5% 91.2% 89.3% 88.0% 84.3% 81.7% 73.9% 65.5% 55.1% 51.7% 36.5% 29.1% 20.3% 19.8% 10.0% 8.1% 4.1% 0.0% 0.0% 0.0%     74.1% 75.1% 71.6% 68.8% 62.4% 60.3% 55.3% 45.3% 34.4% 30.8% 25.1% 20.6% 15.6% 14.0% 9.4% 8.4% 7.1% 4.3% 3.6% 2.7% 2.2% 2.1% 3.2% 0.0% 86.1% 91.9% 91.5% 90.5% 86.5% 83.1% 76.5% 69.0% 62.5% 53.7% 36.1% 30.7% 25.5%            69.2% 70.6% 66.4% 62.2% 54.0% 54.1% 47.5% 42.9% 33.7% 29.1% 27.6% 21.5% 6.2% 0.0% 0.0% 0.0%         86.9% 88.5% 87.8% 86.4% 83.3% 83.2% 80.7% 77.6% 73.6% 73.9% 67.9% 61.7% 54.3% 44.9% 30.6% 23.5% 14.3% 7.6% 2.0% 0.0% 0.0% 0.0% 0.0%  71.2% 72.4% 70.8% 69.1% 64.2% 64.9% 62.4% 59.9% 55.1% 55.5% 50.6% 42.4% 34.3% 26.9% 19.5% 14.7% 8.6% 4.5% 1.6% 0.0% 0.0% 0.0% 0.0%  63.2% 64.0% 61.1% 59.4% 58.6% 57.2% 53.0% 47.7% 42.7% 39.6% 36.4% 30.6% 25.6% 21.2% 15.2% 13.1% 8.9% 5.1% 0.0%      72.3% 74.2% 71.4% 69.5% 66.7% 66.1% 61.0% 52.1% 41.9% 38.8% 34.8% 29.1% 22.4% 18.9% 10.5% 14.2% 9.4%        58.7% 58.4% 55.8% 55.8% 50.9% 52.3% 44.5% 36.8% 29.8% 30.6% 26.2% 24.3% 21.8% 19.2% 15.2% 14.8% 10.4% 7.5% 4.0% 2.4% 1.6% 1.1% 0.0% 0.0% 71.5% 73.2% 72.6% 72.9% 68.6% 66.5% 63.3% 54.8% 41.5% 39.7% 34.9% 30.0% 26.5% 25.4% 25.5% 27.9% 26.1% 26.0% 29.9% 21.4% 17.7% 22.5%   38.6% 38.7% 40.2% 42.6% 47.5% 50.8% 51.3% 51.7% 40.5% 40.3% 39.0% 35.3% 33.5% 28.1% 22.6% 21.0% 16.6% 13.5% 7.8% 3.2% 2.9% 3.1% 2.4% 0.0% 85.6% 87.2% 86.1% 85.0% 80.3% 76.6% 72.7% 69.0% 59.3% 59.8% 60.0% 50.8% 49.8% 47.6% 40.2% 37.8% 34.0% 32.3% 24.2% 20.4% 16.3% 12.2% 7.8% 4.2% 91.3% 92.0% 91.4% 90.5% 83.8% 84.6% 83.6% 84.4% 89.4% 90.2% 90.0% 89.0% 86.0% 82.0% 74.7% 66.7% 59.6% 50.7% 37.9% 31.1% 22.8% 21.3% 15.4% 13.5% 73.5% 74.6% 74.7% 75.2% 70.7% 74.0% 73.4% 70.7% 65.7% 68.2% 61.1% 47.2% 39.3% 34.9% 24.8% 20.1% 13.3% 7.3% 4.3% 0.0% 0.0% 0.0% 0.0%  71.9% 73.3% 70.9% 69.0% 66.9% 66.5% 62.2% 54.5% 49.8% 49.0% 44.1% 41.0% 34.1% 33.8% 19.1% 16.1% 9.4% 0.0%       46.3% 49.3% 48.8% 49.0% 47.3% 44.5% 37.7% 27.9% 19.8% 16.9% 13.4% 11.5% 7.7% 5.4% 3.1% 4.0% 2.6% 1.8% 1.0% 2.0% 0.0% 0.0% 0.0%  69.5% 70.4% 69.4% 69.6% 68.1% 70.1% 66.6% 61.5% 51.8% 51.2% 46.6% 42.3% 36.3% 32.0% 25.2% 25.0% 17.2% 11.8% 4.3% 3.5% 0.0% 0.0%   53.4% 55.9% 54.1% 56.4% 52.9% 53.4% 50.2% 43.7% 37.8% 33.7% 31.3% 35.5% 34.7% 27.1% 17.8% 15.1%         73.0% 73.1% 69.8% 67.2% 62.9% 61.5% 54.3% 46.9% 39.1% 35.3% 31.3% 26.1% 23.7% 27.4% 13.6% 18.0% 0.0%        94.1% 94.2% 91.5% 87.4% 85.3% 80.9% 70.4% 57.2% 39.3% 37.8% 19.7% 16.3% 17.0% 33.8% 31.1% 16.4% 0.0%        58.3% 60.3% 59.3% 57.2% 52.2% 56.4% 58.3% 57.5% 57.6% 58.7% 56.5% 51.8% 46.7% 39.3% 30.0% 26.2% 22.1% 17.1% 10.0% 5.0% 3.0% 3.2% 2.9% 3.3% 93.8% 94.7% 94.4% 93.5% 89.0% 88.9% 88.6% 86.6% 81.6% 82.6% 79.9% 76.4% 70.6% 62.6% 54.4% 43.7% 32.7% 17.6% 10.6% 5.7% 2.7% 2.4% 0.0% 0.0% 74.5% 77.4% 75.0% 75.0% 72.1% 69.8% 65.9% 50.2% 33.2% 25.2% 18.0% 14.2% 14.0% 6.2% 5.5% 5.2% 5.3% 7.4%       87.4% 87.9% 87.5% 87.4% 84.6% 85.7% 85.4% 85.5% 82.8% 83.6% 82.7% 78.9% 72.9% 65.1% 56.4% 50.0% 39.3% 29.2% 19.4% 14.9% 11.7% 12.7% 12.7% 11.5% 66.7% 66.1% 60.2% 57.8% 48.0% 45.5% 39.5% 33.7% 27.3% 25.5% 19.2% 14.4% 9.9% 7.2% 3.9% 3.4% 2.5% 2.4% 1.8% 1.4% 2.0% 0.0% 0.0% 0.0% 61.0% 59.9% 55.9% 53.4% 48.8% 44.3% 35.2% 26.6% 20.6% 16.6% 13.6% 11.0% 7.3% 5.6% 7.3% 0.0%         76.3% 77.9% 77.4% 77.5% 73.3% 75.3% 73.4% 70.2% 66.8% 67.8% 63.8% 55.9% 48.1% 41.1% 32.2% 25.6% 17.1% 12.2% 5.5% 3.9% 1.7% 1.1% 0.0%  64.6% 66.2% 65.3% 65.2% 67.3% 68.0% 62.9% 51.0% 37.6% 34.3% 26.5% 19.2% 7.4% 3.7%           80.5% 81.0% 78.7% 74.9% 67.9% 67.1% 62.2% 53.9% 48.8% 51.3% 49.8% 45.6% 32.2% 27.9% 14.8% 9.1% 5.5% 0.0%       76.5% 78.7% 77.1% 76.8% 69.3% 71.5% 71.6% 70.5% 66.5% 67.8% 65.1% 60.4% 54.7% 48.6% 41.6% 37.3% 30.8% 23.6% 17.9% 15.3% 13.0% 12.8% 11.3% 10.2% 91.1% 90.7% 90.9% 89.9% 87.0% 87.1% 86.4% 84.3% 91.6% 92.4% 91.9% 91.0% 88.3% 85.3% 82.0% 74.6% 63.3% 55.6% 43.8% 31.2% 23.0% 23.4% 20.8% 19.0% 67.9% 66.3% 60.5% 61.5% 54.1% 48.3% 41.2% 36.7% 24.5% 21.3% 17.5% 14.8% 12.8% 10.1% 7.5% 8.6% 6.9% 7.3% 5.7% 5.8% 4.9% 6.0% 5.4% 6.6% 57.2% 56.7% 51.9% 50.3% 46.4% 44.6% 39.3% 33.2% 24.6% 18.9% 16.0% 13.1% 10.2% 8.2% 7.3% 0.0%         66.2% 66.4% 63.6% 62.7% 60.4% 59.1% 52.3% 44.1% 35.2% 34.3% 26.1% 20.2% 16.2% 13.5% 7.5% 7.5% 4.2% 2.2% 0.8% 0.8% 0.0% 0.0% 0.0% 0.0% 83.7% 84.7% 82.5% 81.2% 79.6% 79.7% 75.0% 62.7% 45.4% 41.0% 32.4% 24.1% 17.1% 15.6% 9.2% 6.7% 4.4% 3.6%       89.8% 90.6% 88.2% 86.8% 84.4% 80.4% 74.9% 65.3% 55.5% 52.4% 48.0% 46.3% 38.1% 35.7% 23.4% 18.5% 20.5% 0.0%       35.1% 38.9% 38.2% 40.2% 33.8% 32.2% 38.5% 36.4% 34.3% 33.0% 31.2% 27.8% 22.1% 15.2% 10.0% 6.9% 2.0% 1.9% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 75.6% 75.5% 73.0% 71.5% 66.0% 63.2% 55.6% 47.0% 35.3% 32.4% 29.2% 23.1% 18.3% 17.1% 12.5% 11.9% 9.5% 8.0% 6.9% 4.8% 3.8% 3.6% 2.6% 1.8% 83.4% 84.0% 82.0% 79.9% 73.5% 73.4% 68.1% 63.2% 53.1% 56.6% 54.8% 53.0% 40.8% 35.6% 9.5% 0.0% 0.0% 0.0%       44.6% 48.7% 46.1% 46.9% 36.2% 39.1% 38.2% 34.6% 28.1% 28.4% 25.2% 18.7% 13.1% 10.7% 8.7% 8.1% 5.3% 3.8% 3.5% 0.0% 0.0% 0.0% 0.0% 0.0% 67.1% 70.2% 68.3% 67.3% 64.2% 65.9% 63.8% 57.9% 53.5% 52.9% 47.3% 43.0% 38.2% 33.2% 24.1% 19.6% 14.4% 9.4% 0.0% 0.0% 0.0%    62.0% 64.8% 65.1% 67.1% 62.7% 60.5% 56.8% 49.8% 37.3% 31.1% 29.4% 29.6% 28.8% 34.3% 29.6% 0.0%         91.9% 93.8% 94.4% 92.9% 66.8% 58.1% 44.2% 40.5% 30.3% 27.7% 21.8% 20.1% 14.6%           

参考文献

Category:城市化
Category:美國城市
Category:美国人口流动史