To properly evaluate such data you have to consider scale. If you scale by GDP, you'll see that over the past 15 years, the US debt to GDP ratio is right at the average.
I used date from:
http://www.publicdebt.treas.gov/opd/opdhisto4.htm and
http://www.bea.gov/bea/dn/nipaweb/Ta...wFixed.asp#Mid
to compile the following:
year Debt/GDP Ratio (%)
2002 59.6
2001 57.6
2000 57.8
1999 61.0
1998 62.9
1997 65.1
1996 66.9
1995 67.2
1994 66.5
1993 66.4
1992 64.3
1991 61.2
1990 55.7
1989 52.1
1988 51.0
1987 49.6
1986 47.7
The average over that time is 59.6%. It was 59.6% last year.
If you don't consider scale the data is meaningless. The average debt-to-GDP ratio for ALL countries rated AA credit by Standard and Poor's is 55%. This is quite a normal ratio for large industrial countries.
Note that the time series are off by 3 months because this is end of year GDP compared to the debt on 9/30 of each year (available date). Won't make any real difference though.