Graphic: The U.S. debt limit's steady uphill climb

The so-called "debt ceiling" is the legal limit on how much the U.S. federal government can owe. The government faces an Oct. deadline in which Congress must decide if it will increase the government's $16.7 trillion debt ceiling.

U.S. presidents have had a long history of seeking higher debt limits, as indicated in the charts below, which span increases in actual and inflation-adjusted figures from 1961 to 2012.