In 1942, Robinson was drafted and assigned to a segregated Army cavalry unit in Fort Riley, Kansas. Having the necessary requirements, Robinson and several other black soldiers applied for entrance to an Officer Candidate School (OCS) then located at Fort Riley. Although Army policy had allowed black applicants to enter OCS since July 1941, the applications of Robinson and his colleagues were delayed for several months. After protests by boxing champion Joe Louis (then stationed at Fort Riley) and the help of Truman Gibson (then an assistant civilian aide to the Secretary of War), the men were accepted into OCS. This shared military experience created a friendship between Robinson and Louis. Upon finishing OCS, Robinson was commissioned as a second lieutenant in January 1943. Shortly afterward, Robinson and Isum were engaged.