Which two leagues merged in 1970 to form the modern NFL?

What is the name of the trophy awarded to the AFC champion? In what year was the first Super Bowl played? In which stadium was Super Bowl I played? Which Super Bowl was the only one not designated with Roman numerals? In which city was the NFL founded in 1920, as the American Professional Football Association? In which city is the Pro Football Hall of Fame located? Which team completed the only perfect season in NFL history, including the Super Bowl, in 1972? Which team went 16-0 in the 2007 regular season but lost the Super Bowl?