http://www.census.gov/prod/www/abs/statab1901-1950.htm
1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1924 1925 1926 1928 1929 1930 1931 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1944 1946 1947 1948 1949 1950