Why did the United States appear so uninterested in European troubles during the 1920s and 30s?

After World War I the US attempted to become less involved in world affairs. Americans, after learning of the destruction and cost of World War I, did not want the United States to become entangled in another European conflict which could lead to another devastating war.

Explanation:

the main reason that the constitution did not proclaim all men to be free and equal is because of the issue of slavery.