[1] At the annual Delaware High School All-Star game in June 2017, Henderson was named most valuable player after leading the gold team to a 44–0 victory.
[5] In addition to football, Henderson also started four years on the Smyrna High School baseball team as an outfielder, playing under his father who was the head coach.
[1] After visiting several schools in the Colonial Athletic Association (CAA), Henderson announced his commitment to play college football for the Delaware Fightin' Blue Hens.
[1][7] The following season, he appeared in a total of three games, making his collegiate debut against Lafayette[1] and seeing the most action against Villanova, where he threw a touchdown pass after coming in for the injured Pat Kehoe.
[1] Four games into the 2019 season, Henderson was named starter, replacing Kehoe and becoming the first starting quarterback for the Blue Hens from a Delaware school since Sam Postlethwait in 2001.
[1][7] He was named second-team All-CAA,[10] and led Delaware to the FCS playoffs, where they lost to eventual national champion South Dakota State 42–6, in a game that saw Henderson break his fibula on the first drive.