Short answers, pulled from the story.
The American Football League merged with the NFL in 1970, when all ten AFL franchises joined three existing NFL teams to form the new American Football Conference (AFC). The AFL officially ceased to exist as an unincorporated organization on the 1st of February 1970.
Lamar Hunt conceived the AFL after being unable to buy or secure an NFL expansion franchise. He recruited co-founders including Bud Adams, Bob Howsam, and Max Winter at meetings beginning in March 1959. Joe Foss, a World War II Marine fighter ace and former governor of South Dakota, was named the AFL's first commissioner on the 30th of November 1959.
The original eight AFL teams were the Boston Patriots, Buffalo Bills, Dallas Texans, Denver Broncos, Houston Oilers, Los Angeles Chargers, Titans of New York, and Oakland Raiders. The Patriots, Bills, Oilers, and Titans made up the Eastern Division; the Texans, Broncos, Chargers, and Raiders formed the Western Division.
Three days before Super Bowl III, Jets quarterback Joe Namath responded to a heckler at the Touchdown Club in Miami by saying, "We're going to win Sunday, I guarantee it." The Jets went on to beat the heavily favored Baltimore Colts 16-7 on the 12th of January 1969, in what is considered one of the greatest upsets in American sports history.
The merger was officially announced on the 8th of June 1966. Under the terms, the leagues would hold a common draft and play a championship game between their respective champions, which became the Super Bowl. The AFL agreed to pay $18 million in indemnities to the NFL over 20 years, and NFL Commissioner Pete Rozelle became chief executive of both leagues starting the 26th of July 1966.
The AFL introduced player names on jerseys, scoreboard clocks for official game time, a 14-game schedule (adopted by the NFL a year later), and the two-point conversion, which the NFL did not adopt until 1994, thirty-four years after the AFL introduced it. The AFL also pioneered an equal revenue-sharing television contract, first with ABC beginning in 1960 and later with NBC from 1965.