In 1946, a new professional football league was launched to do battle with the long-established National Football League (NFL). This new league, the All-America Football Conference (AAFC), included eight teams—an Eastern Division with three teams based in the state of New York and another in Miami, and a Western Division with teams in Cleveland, Chicago, San Francisco, and Los Angeles. The AAFC's southern California franchise, which was to compete directly with the newly-relocated Rams of the NFL, was known as the Los Angeles Dons.
The leader of the ownership group was Fernando Gonzalez III, a California businessman & longtime football fan. Other owners included Hollywood notables Louis B. Mayer, Bob Hope, Bing Crosby, and actor Don Ameche.
The Dons' head coach was "Dud" DeGroot, a Stanford football player who had gone on to earn a PhD from that institution. He was the head coach of the NFL's Washington Redskins in 1944 and 1945 before jumping over to the rival AAFC for its debut 1946 season.
The Dons shared the Coliseum with the Rams for home games. Although never filling the mammoth facility, the club made a show of offering vast numbers of tickets for sale at reasonable prices, including 40,000 reserved seats for each home contest priced at $2.50, 15,000 general admission seats costing $1.50, and 8,000 children's tickets priced at just sixty cents.
The team played its first regular season home game in 1946 on against the Brooklyn Dodgers on September 13 in before a Friday night crowd of 18,955 — the first time professional football had ever been played in the Coliseum. The Dons took a first quarter lead on a 55-yard pass from quarterback "Chuckin' Charlie" O'Rourke to Bernie Nygren and never looked back, triumphing 20–14 over the visitors from New York. The Dons opened the inaugural season with three wins and a tie before a rough spell; they finished in third place in the AAFC's Western Division with a record of 7–5–2, out of the playoffs.