Though not specifically stated, Curtis, Cleon and Skip belonged to a unit in the 1st Marine Recon Battalion. This is confirmed late in the movie when Cleon is seen wearing a patch with the 1st Marine Recon Battalion insignia on it.
The film features five actors from Menace II Society (1993), the first feature film by the Hughes brothers. They are: Larenz Tate, Clifton Powell, James Pickens Jr., Ryan Williams and Clifton Collins Jr. Like Menace II Society, Dead Presidents credits Collins Jr. as "Clifton Gonzalez Gonzalez."
Martin Sheen, who makes a cameo appearance as "The Judge" in Dead Presidents, would be in his son Emilio Estevez's feature film The Way (2010), also casted by Mary Vernieu, 15 years later as a protagonist.
Both Larenz Tate & Chris Tucker's characters are hail from The Bronx and end up fighting in the Vietnam war. In Apocalypse Now (1979) Laurence Fishburne's character was also from The Bronx, there's even an Apocalypse Now moment as the sun is shinning behind a flying chopper.