So many American Indians joined the military during WW2 that had all Americans joined at the same proportion, conscription would not have been necessary. The Blackfeet tribe mocked the idea of a draft: “Since when has it been necessary for Blackfeet to draw lots to fight?” 

The Iroquois Confederacy, having declared war on Germany in 1917, had never made peace and so automatically became party to World War II. The Navajo and other tribes were so eager to go to war that they stood for hours in bad weather to sign their draft cards, while others carried their own rifles so they would be ready for battle when they joined up. Unwilling to wait for their draft numbers, one-fourth of the Mescalero Apaches in New Mexico enlisted. Nearly all the able-bodied Chippewas at the Grand Portage Reservation enlisted. In a story that has been attributed to many other tribes as well, Blackfeet Indians mocked the need for a conscription bill. “Since when,” their members cried, “has it been necessary for Blackfeet to draw lots to fight?”

The annual enlistment for Native Americans jumped from 7,500 in the summer of 1942 to 22,000 at the beginning of 1945. According to the Selective Service in 1942, at least 99 percent of all eligible Indians, healthy males aged 21 to 44, had registered for the draft. War Department officials maintained that if the entire population had enlisted in the same proportion as Indians, the response would have rendered Selective Service unnecessary. … The Iroquois took it as an insult to be called up under compulsion. They passed their own draft act and sent their young braves into National Guard units.