Detroit had four early teams in the National Football League before the Detroit Lions. The Heralds played in 1920, and had played as an independent as far back as 1905. The Tigers, a continuation of the Heralds, played in 1921, folding midseason and sending their players to the Buffalo All-Americans. The Panthers competed from 1925 to 1926 and the Wolverines in 1928.

Timothy James Mara was the American founding owner of the New York Giants of the National Football League (NFL). The Giants, under Mara, won NFL championships in 1927, 1934, 1938, and 1956 and divisional titles in 1933, 1935, 1939, 1941, 1944, 1946, and 1958.