Cowart attended Cook County High School in Adel, Georgia. In his senior year, Cowart played third base and also pitched. As a pitcher he went 10-1 with a 1.05 ERA in 73 innings, recording 116 strikeouts and one save. As a batter, he hit .654 with 11 home runs, 59 RBIs and scored 55 runs. He also recorded a 1.206 slugging percentage, a .721 on-base percentage and was 36/36 on stolen bases. His batting average is the second highest in state history for a single season.[citation needed]
After two poor seasons, the Angels assigned Cowart to Inland Empire to start the 2015 season, where he demonstrated an improvement in plate discipline. In June, due to promotions of C. J. Cron, Efren Navarro, and Kyle Kubitza to the major leagues, the Angels promoted Cowart to the Salt Lake Bees of the Class AAAPacific Coast League.[3] The Angels promoted Cowart to the major leagues on August 18, 2015.[4] He made his major league debut that night.