The Koch Family — $130 Billion (Koch Industries)

Charles Koch turned his father Fred's oil refining business into Koch Industries — the largest privately held company in America by revenue ($125 billion). Combined family wealth exceeds $130 billion. The Koch brothers (Charles and the late David) spent over $1.3 billion on U.S. political campaigns since 2010, making them the most politically influential private citizens in modern America. Their network funds think tanks, university programs, and PACs that shape policy from climate regulation to tax law. Love them or hate them — they purchased more political influence per dollar than any family in U.S. history.