Private Mackey was a veteran of World War II. In Korea, he was a member of Headquarters and Service Company, 378th Engineer Combat Battalion, U.S. Army. On 1 May 1951, he drowned trying to swim a breach in a dam on the Ham River near Yoju, South Korea.

Mackey was awarded the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean War Service Medal and the World War II Victory Medal.