The San Francisco 49ers, an original member of the new All-America Football Conference (AAFC), were the first major league professional sports franchise based in San Francisco, and one of the first major league professional sports teams based on the Pacific Coast.[8] In 1946, the team joined the Los Angeles Dons of the AAFC and the Los Angeles Rams of the rival National Football League as the first three teams playing a "big four"-sport in the Western United States,[8] eventually becoming part of the NFL themselves in 1950.