When the NFL was founded in 1920, it used the ‘H’ design for its uprights and placed them on the goal line. In 1927, the league moved the posts back 10 yards, to the back of the end zone.

How the Football Field Was Designed, from Hash Marks to Goal Posts The American football field as evolved over more than 100 years, and with it, the game. Jimmy Stamp. September 24, 2012.