(Figures are in billions of US dollars.)
By way of comparison, I also give below two figures - the increase in debt plus interest paid for 2006, and then for 2008. In the latter case, the increase in debt is that from 30 Sep 2007 to 12 months later, and the interest is the latest available as per here.
In other words, if America had no such debts, she would have $1.45 trillion more per year to spend on other things.
Interest, plus rolling-up more debt, now equates to some 30% of all non-debt-servicing costs of the States and Federal Government.