Because they wanted more opportunities and an end to isolationism. I hope I helped.
I think it's because slavery costs less...just a guess.
Their entry into the war boosted the morale of the other allied nations. Morale completely depleted seems how the war was ultimately a stalemate and lives were being lost needlessly. American entry into the war also discouraged the Axis powers, and later after America's entry the Axis powers began to drop deeper into fear. America was the turning point for the war. The Axis powers were winning and if it weren't for America, then the Axis powers would have prevailed and the world would not be the way it is today. (This is what I think about it, it might not be entirely correct.)
Producers think of workers in two ways, as consumers and as producers of goods and services.
A producer is responsible for putting on the market services and goods. Producers group included government, businesses, investor and individuals and they can hire workers for producing goods and services for them.
A worker as a consumer buys and pays for goods and services.
A worker as a producer can originate economic value, or produces goods and services.
Well this was the beginning of women wanting equality, and also inspired the long process in history for African Americans to attempt freedom. It's eventually gained, but even as free people African Americans are not given the same rights as the old white guys who wanted "freedom" back in colonial days.