Porter taught at Howard University for more than forty years, together with artists such as James Lesesne Wells and Lois Mailou Jones. He headed the Art Department, and served as Director of the Art Gallery from 1953 through 1970. David Driskell, one of Porter's students at Howard, recalled in an interview with Xavier Nicholas that he was the only student in his "Negro Art" class one semester but "He taught that course as though he had a hundred students there, and I was the only one."