Hoping Just would become a teacher, at the age of 13 his mother sent him to the "Colored Normal Industrial Agricultural and Mechanical College of South Carolina", the only 1890 land grant school for the education of Negros in South Carolina, later known as South Carolina State University in Orangeburg, South Carolina. Believing that schools for blacks in the south were inferior, Just and his mother thought it better for him to go north. At the age of 16, Just enrolled at the Meriden, New Hampshire, college-preparatory high school Kimball Union Academy. During Just's second year at Kimball, he returned home for a visit only to learn that his mother had been buried an hour before he arrived. Despite this hardship, Just completed the four-year program in only three years and graduated in 1903 with the highest grades in his class.