Walker was an active member of the American Institute of Architects (AIA) and became its president in 1949. During his two-year presidency he was instrumental in establishing the AIA's College of Fellows which gained approval in 1952. In 1957, on the occasion of the AIA's 100th anniversary, the AIA recognized Walker's extraordinary service to the profession by creating a special award for him, the AIA Centennial Medal of Honor (Gold Medal). The headline of "The New York Times" reporting the award dubbed Walker the "Architect of the Century." To commemorate the event, Walker also wrote and published an autobiography.