Which 1939 laws were designed to prevent the United States from entering further wars?

The Neutrality Acts were a series of legislations passed in the 1930s in response to the growing tensions in Europe and Asia, with the aim of keeping the United States out of foreign conflicts. These laws reflected the American public's desire to avoid the entanglements that led to involvement in World War I. The Acts imposed restrictions on trade and travel with warring nations and prohibited American citizens from serving in overseas conflicts.

As tensions escalated in Europe, particularly with the rise of fascism and the onset of World War II, these laws were intended to keep the United States neutral by limiting economic and military involvement with belligerent nations. The Neutrality Acts represented a significant point in American foreign policy, emphasizing the country's isolationist stance at that time.