The Academy of Country Music Awards (ACM for short) was established in Los Angeles in 1964 to promote the development of country music in the western States of the United States. Its members were mainly from the western States, etc. (Because the center of country music is mainly in the southeastern States of the United States, I personally thought that maybe the country musicians from the western States might be discriminated against at that time? But now, of course, they are all in harmony. )
CMT, short for Country Music Television, is a cable TV network that basically broadcasts American country music MV. It is an award mainly for TV programs related to MV or country music, which is produced by online voting of fans.