Arlene H. Eakle blogged last night about "Gretna Greens"—out-of-town spots that welcomed eloping couples.
Military posts on the frontier, like Crown Point NY, Southwest Point TN, could be gretnas. People from border states along international boundaries for Canada and Mexico often slipped over the boundary to marry. River Towns along the Ohio, the Mississippi, the Connecticut, the Hudson, the Missouri Rivers. Keokuk, Lee County, IA was a gretna green along the Mississippi; it was also a favored place of marriage for Irish ancestors coming both from the Eastern states and up the River. [Link]