"The recent economic slowdown led to sharply higher deficits in recent years, which led to a series of debt limit increases. The Housing and Economic Recovery Act of 2008 (H.R. 3221), signed into law (P.L. 110-289) on July 30, 2008, included a debt limit increase. The Emergency Economic Stabilization Act of 2008 (H.R. 1424), signed into law on October 3 (P.L. 110-343), raised the debt limit again. The debt limit rose a third time in less than a year to $12,104 billion with the passage of the American Recovery and Reinvestment Act of 2009 on February 13, 2009 (ARRA; H.R. 1), which was signed into law on February 17, 2009 (P.L. 111-5). Following this measure, the debt limit was subsequently increased by $290 billion to $12,394 billion (P.L. 111-123) in a stand-alone debt limit bill on December 28, 2009, and by $1.9 trillion to $14,294 billion on February 12, 2010 (P.L. 111-139), as part of a package that also contained the Statutory Pay-As-You-Go Act of 2010. Following enactment of the Budget Control Act of 2011 (P.L. 112-25) and the submission of a certification letter from President Obama to the Congress, the debt limit was increased on August 2, 2011, by $400 billion, to $14,694 billion."
CRS Report for Congress, RL31967