"A statutory limit has restricted total federal debt since 1917 when Congress passed the Second Liberty Bond Act. Congress has voted to raise the debt limit ten times since 2001. [...] A debt limit increase was included in the Housing and Economic Recovery Act of 2008 (H.R. 3221) and signed into law (P.L. 110-289) on July 30. 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 was increased for the third time in less than a year with the passage of 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), which raised the debt limit to $12,104 billion. The House's adoption of the conference report on the FY2010 budget resolution (S.Con.Res. 13) on April 29, 2009, triggered the automatic passage of H.J.Res. 45 to raise the debt limit to $13.029 trillion. In August 2009, Treasury reportedly said that the debt limit would be reached in mid-October, although the Treasury later stated that the limit would not be reached until mid or late December 2009. H.R. 4314, passed by the House on December 16, 2009, and by the Senate on December 24, raised the debt limit to $12.394 trillion when the President signed the measure (P.L. 111-123) on December 28. On January 28, the Senate passed an amended version of H.J.Res. 45, which the House passed on February 4 and the President signed on February 12."
CRS Report for Congress, RL31967