State Politics and Policy Quarterly Data Resource

Quoting the site, the SPPQ Data Resource is “a series of data sets than include more than 50 state-level indicators on everything from crime rates to unified partisan control of state government. Many of these variables are available by state for a 20-year period (approximately 1974 to 1999). See the codebook for more detail. Geographic coverage: the 50 U.S. states, not including Washington D.C..
The web site is sponsored by The Practical Researcher section of State Politics & Policy Quarterly, the official journal of the State Politics and Policy Organized Section of the American Political Science Association, and the Department of Political Science of the University of Lincoln Nebraska.” Don’t miss the page of annotated links to other state data sources.