The Bills began play as an original franchise of the American Football League (AFL) in 1960. The club joined the NFL as a result of the AFL–NFL merger for the 1970 season. The 1964 and 1965 Bills were the only teams representing Buffalo that won major league professional sports championships ("back-to-back" American Football League Championships). The Bills are the only team to win four consecutive conference championships and are the only NFL team to lose four consecutive Super Bowls. The team was owned by Ralph Wilson from the team's founding in 1960, until his death in 2014 at the age of 95. After his death, Wilson's estate reached an agreement to sell the team to Terry and Kim Pegula, which was approved by the other NFL team owners on October 8, 2014. The team has featured many of the league's most prominent and popular players, including QB Jack Kemp, FB Cookie Gilchrist, G Bob Kalsu, RB O. J. Simpson, DE Bruce Smith, QB Jim Kelly, RB Thurman Thomas, and WR Andre Reed. The Bills have the longest active playoff drought in any major professional sport: they have not made the playoffs since 1999 and are the only team that has not appeared in the NFL playoffs so far in the 21st century.