Along with the Four Chaplains and their families, most of the other characters are based on real servicemen and civilians who were aboard the USAT Dorchester.
American counterculture author Jack Kerouac was briefly assigned to the USAT Dorchester while enlisted in the Navy. While aboard the Dorchester, Kerouac struck up a friendship with the ship's chief cook, Old Glory. Kerouac was sent to a Naval hospital after suffering severe headaches mere days prior to the Dorchester's fateful final journey.
William G. (Bill) Bunkelman, the final USAT Dorchester survivor, passed away 1 January 2019 at the age of 98.
As a "thank you" gift for his tribute to the Four Chaplains, Writer/Director Christopher Stevens was presented with a 1933 yearbook from Rutgers University, the year Chaplain Clark V Poling graduated from that institution. The gift was sent from an anonymous source.
Writer/Director Christopher Stevens met several of the Dorchester survivors in the 1990s and into the 2000s while conducting research. One particular survivor was First Sergeant Michael Warish (1912-2003). Warish had been an atheist until he witnessed "they there were, surrounded by men as the ship was sinking, conducting one last church service. It was either out of madness or joy. My ankle was busted. I'd cracked my head wide open in the blast when tossed from my bunk. I crawled to the top deck and saw them gathered there. I promised God if he'd get me off the ship, I'd change. From the water, I watched her sink with those men singing and praising until the ship was gone. I changed. How could I not after seeing that demonstration of faith?"