Re: Proof

The United States public debt, commonly called the national debt, gross federal debt or U.S. government debt, is the amount of money owed by the United States federal government to creditors who hold U.S. Debt Instruments. As of September 2007, the total U.S. federal public debt was $5.6 trillion. [1]
Sauce: Government - Schedules of Federal Debt – Daily, Unaudited