There has never been a million dollar bill printed. The $100,000 gold certificate was the largest bill ever printed, but it was not circulated to the public.
The Bureau of Engraving and Printing is in charge of making all of the paper money for the United States. Although larger-denomination bills have been made, the largest bill that is regularly made is the $100 bill.
Paper money is made up of three-quarters cotton and one-quarter linen. Changes are made to paper currency to deter those who produce counterfeit bills. The Bureau of Engraving and Printing is located in Washington, D.C., and is part of the U.S. Department of the Treasury.