Question

To what extent was the untied states truly
isolationist in its foreign policy in the years prior to 1941.

Answer 1

Isolationists, or probably more accurately "non-interventionists", believed in putting America first and solving its own problems. They saw America as a country that could stand alone in the world. The Crash in '29 and the Great Depression that followed also forced many to focus even more on their own problems fueling their arguments not take on the "burden" of anyone else.

As a result, many of them also saw the war in Europe as a "European Problem" and wanted no part of it especially after the horrors of WW1. They didn't want to be dragged into what they felt was a "foreign problem".

A group called the America First Committee was even set up in 1940 to promote anti-war ideals of which Charles Lindberg was a member. And then the Japanese attacked in 1941. A few days later, Hitler declared war on the United States as a show of solidarity with Japan, forcing the issue and silencing the isolationists.