Answer & Explanation:
Following the end of the First World War, the United States made hard efforts to avoid its involvement in world affairs. The following are some of the efforts
League of Nations: Even though President Wilson tried hard for its membership, the Senate refused to join the League of Nations. Americans, after experiencing the devastation due to the First World War did not want the U.S. to interfere in another European conflict.
Immigration: The United States closed its door for immigration. Earlier they banned Chinese, Japanese, and other Asians but later on, they even banned the Europeans.
Tariffs: The U.S. placed high tariffs on imports to keep foreign products out of the American markets.
America set high tariffs on imports to keep out foreign products.