For American settlers, tattooing would have been most closely associated with Native Americans or criminals, and deemed unacceptable for “civilized” people….
But that first started to change during the Revolutionary War. American sailors decorated themselves with symbols of their newborn country—the “goddess” Columbia, the face of George Washington, the American flag. For these sailors a patriotic tattoo served both as personal and group identification…
…The Civil War helped tattooing begin a transition from the military to wider society, and ushered in the style of classic tattooing unique to America. Tattooing had long been widespread among sailors, but during the war men who would never have considered getting a tattoo before wanted a way to show their allegiance to their cause and to identify themselves in the event of death.
Aïda Amer and Sarah Laskow at Atlas Obscura