How did US contribute the allied cause before and after it entered the war?

Before entering World War II, the United States contributed to the Allied cause through programs like Lend-Lease, which provided military and economic aid to countries such as Britain and the Soviet Union. Additionally, the U.S. supported Allied nations by supplying arms, food, and raw materials, while also engaging in diplomatic efforts to strengthen alliances. After entering the war in December 1941, the U.S. significantly bolstered Allied forces with troops, resources, and industrial production, playing a crucial role in key battles and campaigns in both the European and Pacific theaters. This commitment helped turn the tide against Axis powers and ultimately contributed to the Allies' victory.