"The Letter Men" is based on the real love letters written by Gilbert Bradley to his sweetheart, Gordon Bowsher during WWII. Exchanged between 1938 and 1941, the letters were uncovered in 2017 and represent the largest known collection LGBTQ love letters from that time period. Using text from the actual letters, "The Letter Men" follows the two men as their fight to keep their love alive in the face of war and loss.

After the PTA of a conservative high school in Indiana bans same-sex couples from attending the annual prom, a gang of flamboyant Broadway stars try to boost their image by showing up to support two lesbian students.