Fightin' Marines #15 (St. John, August 1951) is — despite the "#15" on its cover — the first issue of this classic war comic, telling fictional combat tales of the United States Marine Corps. The issue features separate adventures starring "Tripoli" Shores and Leatherneck Jack, alongside the war stories Han River Death Trap and Fly…or Die!, a two-page text piece (Troop Ambush That Failed), and an early appearance of the military-comedy mascot Canteen Kate. The cover and key interior art — including the Leatherneck Jack and Canteen Kate features — are by the celebrated artist Matt Baker.

The book's odd numbering is a quirk of St. John Publications' business practices: rather than launch a new title at #1, the publisher converted its Western series The Texan (issues #1–14) into a Korean War-era war comic, resuming as Fightin' Marines #15 before confusingly resetting the count to #2 the following month. The switch reflected the early-1950s boom in military comics driven by the Korean War. Matt Baker — one of the first prominent African-American artists in the American comics industry, famed for his "good-girl art" on Quality's Phantom Lady — supplied much of the early series' art, and his creation Canteen Kate proved popular enough to headline her own title in 1952. St. John later sold Fightin' Marines to Charlton Comics (1955), which ran it until 1984.

For collectors and historians today, this first issue is prized for its Matt Baker artwork and its status as the launch of a long-lived war title. It offers a vivid snapshot of Korean War-era combat comics and the era's blend of action and service-comedy. Because no copyright renewals appear to have been filed for the St. John run, the issue is widely regarded as public domain and survives through digital archives and modern reprint collections of Baker's work.