Briefly describe one development that contributed isolationist sentiment in the united states from 1919 to 1940.

World war I

Explanation:

After the loses due to the US involvement in first world war isolationist sentiment grew that seek to discourage any involvement by the government in the businesses of other countries.

Also many wanted the US economy to become self sufficient inorder to avoid dealings with other nations. This lead to lesser military alliance by the US government.