From the Summary: "The United States has been free of a national debt for only two years, 1834 and 1835. In its first year, 1790, the country faced a debt of $75 million. From FY1998 to FY2001, the federal government ran budget surpluses. Since then, the budget has returned to deficit, and the debt had risen to $5 trillion by 2007. It rose to a high of 108.6% of gross domestic product (GDP) at the end of World War II; declined to a post-World War II low of 23.8% of GDP in 1974; and, then, rose to another high of 49.5% of GDP in 1993. […] As a result, the private capital stock inherited by future generations is likely to be smaller and their real income or output will likely be lower. It is the reduction in future output that constitutes the burden of the national debt and it is a burden borne largely by future generations. It is a burden that cannot be decreased by borrowing abroad even though foreign borrowing could leave unchanged the size of the private capital stock. Crucial to the consensus view (and other views) is the assumption that the economy is fully employed. And the burden discussed must be regarded as a gross burden in the sense that certain intangible gains must be set against it such as freedom from tyranny and domination by a foreign power that might have occurred had the United States lost such a contest as World War II."
CRS Report for Congress, RL30520