[3] Garrison was educated at the Salem School in Lincolnton and South Fork Institute in Marion.
[2] Planning to study medicine,[1] Garrison enrolled at the Peabody College, where he changed his mind and received another master's degree in educational psychology in 1916 instead.
[1] He served in the Walter Reed Hospital in Washington, D.C. and helped create the Alpha Intelligence Test.
[1][2][4] During his tenure as president, he expanded the Departments of Business Education, Home Economics, and Music.
[1] He also wrote spelling books with Bruce Ryburn Payne and Beatrice Irene Bryan.
[3] Garrison served on the Tennessee State Board of Education, the Nashville Area Council of the Boy Scouts of America, and the Board of Trustees of Meharry Medical College, a historically black medical school in Nashville.
His funeral took place in the Social-Religious Building of Peabody College, and he was buried at Mount Olivet Cemetery.
[2] On May 9, 1946, Horace Greeley Hill Jr. donated a portrait of Garrison painted by Max Westfield to Peabody College.