World War II brought new prosperity to many Americans. Who benefited most from the wartime economy? What financial limitations did various members of society face, and why?
The answer to this would be substantially different if you are asking about the impact of World War II as a whole than if you are asking about the economy during the years 1941 to 1945. In other words, WWII certainly brought new prosperity to many Americans, but it brought that prosperity to different Americans in the actual war years than it did in the years after the war.
After the war, prosperity came to many Americans as a result of the war. This came about in large part through the GI Bill. The GI Bill allowed many Americans from all classes of society to go to college. This allowed them to become part of the middle class. It also allowed many Americans to buy their own homes for the first time. This helped them and it helped people like those who got work building the homes in the new suburbs.
But your question asks about the war years themselves. So let me turn my attention to that time. I would argue that the war years did not enrich as many Americans. Those who benefited most from the wartime economy fit into two main groups. Perhaps the group that benefited the most was the group that owned the big companies. Big industrial companies made huge amounts of money making the things that were needed for the war effort. However, the benefits did trickle down. Everyone who was able to work during the war (rather than having to go off to fight) tended to make much more money than they previously had. Wages increased as there was a very tight labor market. Income for farmers and farm workers increased because the need for agricultural products was so high. Essentially everyone realized some economic benefits.
The main “financial limitation” that most people faced during the war was a lack of things on which to spend their money. Very many kinds of goods were rationed during the war. This meant that, even though people had money, they could not spend it because there was not that much that was available for sale.
Thus, the war did bring about prosperity, but that prosperity was mainly felt after the war when there were more consumer goods available and when the men who had been fighting returned and reaped the benefits of the GI Bill.