We got the debt limit, or the debt ceiling, in 1917. Before then, Congress had to give its approval every time the Treasury Department issued a bond.
Julian Zelzer, who teaches U.S. history at Princeton, says that, during the run-up to World War I, lawmakers recognized this wasn't very inefficient.
"Congress decided to create this debt ceiling to give more flexibility and efficiency to the federal government to handle a growing debt," he says.
Congress sets the debt limit -- the amount of money the government can borrow to pay what it owes. Sarah Binder, who teaches political science at George Washington University, says lawmakers realized, early on, that gave them a lot of power.
"This was a tool for trying to get Congress and the president to agree to other things," she says.
When President Eisenhower tried to raise it, he clashed with Republicans and Southern Democrats. The same thing happened to President Kennedy:
"The debt limit does not and cannot control expenditures," said Kennedy.
Raising the Debt Ceiling: A Timeline
Do you know how many times the debt ceiling has been raised since 1940? View our interactive timeline to see each time the debt ceiling was raised, which party was in office at the time, and how close we got to hitting the debt ceiling. View more.
In the middle of negotiations over the fiscal cliff, President Obama said it would be easier if the administration no longer needed congressional approval to raise the debt limit. Well, that didn't interest House Speaker John Boehner.
"Congress is never going to give up our ability to control the purse. And the fact is that the debt limit ought to be used to bring fiscal sanity to Washington, D.C.," Boehner has said.
But Julizan Zelizer says that's not what the debt limit was designed to do:
"The debt ceiling isn't the way to really control spending. It's the budget process."
Something congress hasn't been good at. It hasn't passed a budget since 2009.