Just for persepective---here are previous National Debt limits and the dollar amount increases authorized by Congress...

Here is the dollar amount of the various national debt limits set in the past 10 years and the dollar amount change authorized by Congress from one level to the next.

Date                          New Limit        Change from previous limit

June 28, 2002       $6,400  (T)        $450 (Billion)

May 27, 2003       $7,384                $ 984 (B)

Nov. 19, 2004      $8,184                 $800 (B)

Mar. 20, 2006       $8,965                $781 (B)

Sept. 29, 2007      $9,815                $850 (B)

July 30, 2008     $10,615                $800 (B)

Oct. 3, 2008       $11,315                $700 (B)

Feb. 17, 2009     $12,104               $789 (B)

Dec. 28, 2009     $12,394              $290 (B)

Feb. 12, 21010   $14.294               $1.9  Trillion

Aug 2, 2011       $16.694             $2.4 (Trillion)