The United States debt ceiling is a limit set by congress that tells how much money the government can borrow at any given time. Its basic purpose is to try to lower the national debt or prevent excessive borrowing. The debt ceiling was created in 1917 under the Second Liberty Bond Act. It was designed to fund the US as it entered World War I. Before the creation of the debt ceiling, the president determined how much debt could be incurred in a given time. This was changed in 1917 to prevent the president from having too much borrowing power. The debt ceiling in 2011 was 14.3 trillion dollars.