The AFL and NFL completed their merger in 1970. Although the agreement was announced on June 8, 1966, the two leagues continued separate regular seasons through 1969 before becoming one league for the 1970 season.
The merged NFL was divided into the American Football Conference and National Football Conference. All ten AFL teams joined the AFC, along with the Baltimore Colts, Cleveland Browns, and Pittsburgh Steelers. The other thirteen former NFL teams formed the NFC.
The merger also transformed the Super Bowl. Before 1970, it was an interleague championship game between the AFL and NFL champions. After the merger, it became the NFL’s championship game, with the AFC and NFC champions meeting for the title.
A common mix-up is 1966, the year the merger agreement was announced. Another is 1970 being treated as merely a realignment year; it was the first season played under the unified league structure.