U.S. Congress, Senate Library, Presidential Vetoes ... 1789-1968; U.S. Congre...

National Governors Association, Washington, DC, 1970-87 and 1991-2007, Direct...

Except as noted, The Council of State Governments, Lexington, KY, The Book of...

National Conference of State Legislatures, Denver, CO, State Legislatures, pe...

Center for American Women and Politics, Eagleton Institute of Politics, Rutge...

Joint Center for Political and Economic Studies, Washington, DC, Black Electe...

National Association of Latino Elected and Appointed Officials (NALEO) Educat...

U.S. House of Representatives, Office of the Clerk, Statistics of the Preside...

U.S. Federal Election Commission, press release of January 2007. For more inf...

Board of Governors of the Federal Reserve System, Statistical Supplement to t...