Sean Penn and a handful of other actors received military horsemanship training for the scenes as the leader of the school's mounted cavalry. He later stated "It's not like riding out on a backwoods trail-The trick is to salute, control the horse, keep in step with the other riders and try not to fall off."
Prior to the production of the film, the key actors -Timothy Hutton, Sean Penn, Tom Cruise and others - were required to participate in a 45-day-long period of orientation with the students of Valley Forge Military Academy. They were given uniforms, borrowed from their real life counterparts at the school and given authentic military haircuts. They slept in campus barracks and were subjected to the same rigors and hardship that all Valley Forge cadets went through. While most of the actors enjoyed and excelled at their orientation, Cruise opted to leave the training for the comforts of a nearby hotel until filming began.
More than 2000 actors auditioned for Sean Penn's role as Cadet Captain Alex Dwyer, which Penn won after being seen in a fiery performance in an off-Broadway play "Heartland" by the film's casting director Shirley Rich.
Due to the 1980 Screen Actors Guild writer's strike, filming on the campus of Valley Forge Military Academy took much longer (60 days) than originally planned. It caused such a disruption that the commandant of the school subsequently advised his colleagues not to allow film productions at their schools. The next year, both Valley Forge and the Citadel military academies denied filmmakers of La loi des seigneurs (1983) access to their grounds, leading it to be filmed in England instead.
Tim Riley, who played Hulk, went on to serve in the U.S. Army Reserves, and was the commander of the 1018th QM Company in Schenectady, New York from 1988-1990.