U.S. Political Stats draws on a number of authoritative CQ Press sources for elections data. Data have been adapted from these CQ Press sources:

• America Votes biennial series
• America at the Polls series

The America Votes series, covering presidential, gubernatorial, House, and Senate general elections and primaries every election cycle, was first created by Richard M. Scammon and Alice V. McGillivray of the Elections Research Center, Washington, D.C., in 1956. Since 1996 the series has been edited and compiled by Rhodes Cook. The series includes the following:

• Scammon, Richard M., Alice V. McGillivray, and the Elections Research Center. America Votes 15. Washington: CQ Press, 1983.
• Scammon, Richard M., Alice V. McGillivray, and the Elections Research Center. America Votes 16. Washington: CQ Press, 1985.
• Scammon, Richard M., Alice V. McGillivray, and the Elections Research Center. America Votes 17. Washington: CQ Press, 1987.
• Scammon, Richard M., Alice V. McGillivray, and the Elections Research Center. America Votes 18. Washington: CQ Press, 1989.
• Scammon, Richard M., Alice V. McGillivray, and the Elections Research Center. America Votes 19. Washington: CQ Press, 1991.
• Scammon, Richard M., Alice V. McGillivray, and the Elections Research Center. America Votes 20. Washington: CQ Press, 1993.
• Scammon, Richard M., Alice V. McGillivray, and the Elections Research Center. America Votes 21. Washington: CQ Press, 1995.
• Scammon, Richard M., Alice V. McGillivray, and Rhodes Cook. America Votes 22. Washington: CQ Press, 1998.
• Scammon, Richard M., Alice V. McGillivray, and Rhodes Cook. America Votes 23. Washington: CQ Press, 1999.
• Scammon, Richard M., Alice V. McGillivray, and Rhodes Cook. America Votes 24. Washington: CQ Press, 2001.
• Scammon, Richard M., Alice V. McGillivray, and Rhodes Cook. America Votes 25. Washington: CQ Press, 2003.
• Scammon, Richard M., Alice V. McGillivray, and Rhodes Cook. America Votes 26: 2003-2004. Washington: CQ Press, 2006.
• Scammon, Richard M., Alice V. McGillivray, and Rhodes Cook. America Votes 27: 2005-2006. Washington: CQ Press, 2008.
• Scammon, Richard M., Alice V. McGillivray, and Rhodes Cook. America Votes 28: 2007-2008. Washington: CQ Press, 2010.
• Rhodes Cook. America Votes 29: 2009-2010. Washington: CQ Press, 2012.
• Rhodes Cook. America Votes 30: 2011-2012. Washington: CQ Press, 2014.

The data in this series are compiled from final, official results obtained from election authorities in each state. On occasion, states may belatedly report vote total changes that occur after publication of the volumes. The editors and CQ Press have made every attempt to incorporate changes and corrections in the data. Where possible, footnotes and notes regarding specific elections or vote totals have been retained in this Collection or integrated into the data.

The America at the Polls series, covering presidential general elections and primaries, includes the following:

• McGillivray, Alice V., Richard M. Scammon, and Rhodes Cook. America at the Polls 1960 to 2000: John F. Kennedy to George W. Bush. Washington: CQ Press, 2001.