John Payne and Maureen O'Hara also appeared together in another "Tripoli"-named film--To the Shores of Tripoli (1942).
There is a mural at The Basic School at the Marine Corp base in Quantico, VA. The mural depicts the battle between Marines led by Lt Presley O'Bannon, played by John Payne in the movie, and the Barbary pirates. The artist used a photo of Payne to paint O'Bannon.
At 1:22:17 a Marine gives O'Bannon a US Flag. That Marine is played by Jack Pennick. Pennick joined the US Marines as a young man serving from 1912 through WWi. He rejoined the military in WWII snd served in John Ford's Field Photographic Unit