His acceptance was delayed due to an investigation into his column at The Black Dispatch, which had caused him to be labeled a troublemaker.

[12] During his time with the Marines, Stewart rose to the rank of Steward First Class and was honorably discharged on December 6, 1945.

[15] He left the position when he joined the Marines, but was re-elected President of the Oklahoma City NAACP Chapter upon his return, where he began working to ensure equal employment opportunities for black people.

[16] Stewart worked to get jobs for blacks in several places where they had been previously rejected or unable to move up the chain of command, such as Tinker Air Force Base.

[17] As president of the OKC Chapter of the NAACP, a position he would hold until 1957,[18] Stewart helped to end the segregation of schools, especially with the integration of the University of Oklahoma, on which he worked with Thurgood Marshall[19] and others to help Ada Lois Sipuel Fisher become the first black law student to attend[20] and Prentice Gautt become the first black athlete to attend.

In 1947, Stewart and other leaders drafted a plan to create regional offices in order to allow for the better management of the organization.

In 1948, following the approval of the plan, Stewart was selected to be on the board of directors for the Southwest Region, a role he held for 24 years.

[18] The American Association of Blacks in Energy's (AABE) annual award for meritorious service is named for Stewart.