David H. Koch Charitable Foundation

David and Charles Koch control Koch Industries, the second-largest privately owned company and the largest privately owned energy company in the nation; they have a combined net worth of approximately $4 billion, placing them among the top 50 wealthiest individuals in the country and among the top 100 wealthiest individuals in the world in 2003, according to Forbes. The foundation has contributed millions of dollars to Citizens for a Sound Economy and the Cato Institute.

*This foundation provided funding for the organization Citizens for a Sound Economy. In 2004, Citizens for a Sound Economy split into two groups: FreedomWorks and Americans for Prosperity. In the Conservative Transparency database, FreedomWorks' financial data includes data from Citizens for a Sound Economy.