Answer:
On May 18, 1917, Congress passed the Selective Service Act, which authorized the Federal Government to temporarily expand the military through conscription. The act eventually required all men between the ages of 21 to 45 to register for military service.
Explanation:
Mongols favored trade even before Ghenghis khan, they hunted/herded very few were weapon makers or potters/weavers, many items they needed to living had to be traded. As Ghenghis khan rose to he realized the Mongol army was gonna need many things for battles. To facilitate trade Ghenghis offered protection to merchants that came from east and west, offered higher status for merchants allowed by the Chinese or Persians who despised trade and traders.