Why do scholars study american indians by language group? why were there so many american indian languages? plaese

In the 1950s, the u.s. government encouraged american jazz musicians to perform in the soviet union, which was an enemy of the u.s. at the time. of what foreign policy goal is this a good example? strengthening world economic growth improving education for the global population advancing the growth of democracy and good government increasing understanding of american values and creating a receptive international environment