Final answer:
The Neutrality Acts of the mid-1930s were designed to keep the United States out of foreign conflicts, initially by banning the sale of arms and lending to warring nations. Amendments to these acts, especially the 'cash-and-carry' provision, gradually shifted American policy towards aiding Allies before the country's formal entry into WWII after the attack on Pearl Harbor.
Step-by-step explanation:
The Neutrality Acts of the mid-1930s were a sequence of legislations passed by the United States Congress in response to the growing conflicts overseas, particularly in Europe and Asia. These acts were aimed at ensuring that the United States would maintain its neutral stance and avoid becoming embroiled in another conflict after the experiences of World War I. The initial Neutrality Act of 1935 instituted a ban on the sale of armaments to warring nations with the hope of preventing the US from becoming involved in foreign wars. Over time and with rising global tensions, subsequent acts in 1936 and 1937 refined these measures.
The Neutrality Act of 1936 extended the provisions by prohibiting the lending of money to belligerent countries. As the potential for war grew with events such as the invasion of Ethiopia by Italy, the Spanish Civil War, and the aggression of Japan in China, the US faced challenges in sticking strictly to these neutrality principles. President Franklin D. Roosevelt's administration sought avenues for providing non-military assistance to countries struggling against fascist aggressors.
The 1937 Act introduced the cash-and-carry provision, allowing belligerents to purchase non-military goods, provided they paid in cash and transported the goods in their own vessels, circumventing the transportation ban on American ships. However, the provision still favored countries like Britain and France who had control over the seas and could actually reach US territories to carry goods back home, over nations like Germany.
When war officially broke out in 1939, the neutrality facade thinned, and the US gradually moved from strict neutrality towards a policy that would support Allies against the Axis powers. By end of 1939, the Neutrality Acts were adjusted to allow sales of military goods to belligerents, marking a shift in US foreign policy and a move towards an 'arsenal of democracy' that would eventually play a significant role in WWII.