The national government has actually never defaulted, but what has happen is that several individual state governments have defaulted in the 1840s. After the war against the British in 1812 and in combination with investments in US infrastructure, the US increased its borrowing. In 1837, a financial panic occurred which culminated in a depression. By 1844, $60 million worth of state improvement bonds were in default.
The defaults did have some positive effects on the long-term side:
- Major financial reforms - such as restricting state investments in private corporations and limits on the amount of debt governments could issue. These reforms had not probably happened if the state governments had been bailed out by the national government. Is a default the only way to prevent people from spending more money than they have?
- The dollar did not collapse and investors were soon lending again to US states. The risk of another default decreases after the original default
One can also draw a parallel to the current Euro Zone crisis. The US is a similar currency union, and if the "US Zone" survived when some of its members defaulted in the 1840s, can the Euro Zone survive if Greece defaults?
Source: The American, Financial News Online