Saving Private Ryan is partly based on a true story.
It wasn’t based on the Sullivan brothers, five brothers who were all killed serving in the Navy during WWII on the USS Juneau. Actually, it was based on the Niland brothers – four brothers who served in the Army during WWII. Three of the brothers (Robert, Preston, and Edward) were supposedly killed in action, which caused the remaining brother (Fritz) to be shipped back to the U.S. so the Niland family wouldn’t lose all of their sons. Edward, who was thought dead, was eventually found alive following his escape from a Japanese prison camp in Burma.