Baltimore's first professional football team, the Colts of the AFC were established in 1947. The team played at Baltimore Stadium, but were disbanded three years later. In 1953, the NFL awarded Baltimore a franchise, which also were named the Colts.

The Baltimore Colts played their inaugural first game at Memorial Stadium on September 27, 1953. Over 46,000 fans filled the two tier structure to watch the Colts play the Chicago Bears. Memorial Stadium underwent several alterations during its existence. Box seats were added in 1961, increasing the capacity to 49,000. By 1964, the upper deck was lengthened, with two sections added at both ends of the horseshoe. The seating capacity was increased to 54,000 for baseball and 65,000 for football.