In a very interesting WSJ article (I managed to read it without a subscription), Tom Sargent writes:

Did the federal government do the right thing in refusing to bail out the states in the early 1840s? By doing so, the federal government reset its reputation vis-a-vis the states, telling them in effect not to expect it to underwrite their profligacy. In the short run, that cost the federal government substantially in terms of its reputation with its own creditors. Federal credit abroad suffered along with state credit. But in the long run, the decision exposed state governments to continuing market discipline, making future crises and requests for federal bailouts less likely.

If the federal government had chosen to bail out the states a second time, it probably would have taken greater control over state taxes and revenues in order to prevent yet another bailout situation. Refusal to bail out the states was thus a pivot point in sustaining a federal system in the United States. It led the states to discipline themselves by rearranging their constitutions in ways designed to allow them to retain freedom and responsibility for taxing and spending within their borders.

Europeans today might be tempted to say “yes” to bailouts. Or they might also recall a time when Americans preserved their own federal system by saying “no.”