The main purpose of the Selective Service Act of 1917 was to make sure that when the country goes to war, it has enough troops to win. The first Selective Service Act was enacted during the first world war. Its main purpose was to get men registered for the draft, which in turn forced men to go to war to meet troop demands.
African American Men they were involved in the civil war from both sides. One by choice one by force. 179,000 African Americans fought but a total of 620,000 fought
The answer to the question is it marked the beginning of the end of Nazi tyranny across Europe, the victorious turning point of the allies in the second world war.