The number one contributor to political parties in 1995-96 was Philip Morris, the largest tobacco company in the world. This report lists all of the top 100 contributors.
The Center for Responsive Politics is a non-partisan, non-profit research group based in Washington, D.C. that tracks money in politics, and its effect on elections and public policy. The Center conducts computer-based research on campaign finance issues for the news media, academics, activists, and the public at large.