How has the National Debt Grown Over the Years?

Year    Gross Debt in $Billions undeflated from the OMB
1940	50.7
1950	256.9
1960	290.5
1970	380.9
1980	909
1990	3,206
2000	5,629
2001	5,770
2002	6,198
2003	6,760
2004	7,355
2005	7,905
2006	8,451
2007	8,951
2008	9,986
2009	11,876
2010	13,529
2011 	> 15,000 (as November 17, 2011) 

For a DAILY look at the US National Debt you can go here.

Here is a nice long description of the debt from the OMB (Office of Management and Budget).