1970: This was an eventful year. The American Football Conference was formed on May 17, 1969, prompting the entry of several teams when the American Football League merged with the NFL: the New England Patriots (previously the Boston Patriots), the Buffalo Bills, the Cincinnati Bengals, the Denver Broncos, the Houston Oilers, the Kansas City Chiefs, the Miami Dolphins, the New York Jets, the Oakland Raiders, and the San Diego Chargers. The San Diego team moved in 2017, becoming the Los Angeles Chargers. The Houston Oilers relocated to Tennessee in 1998 and played for two years as the Tennessee Oilers before becoming the Tennessee Titans in 1999.
1976: The Seattle Seahawks and the Tampa Bay Buccaneers entered the league.