The two-story brick mass of Monroe County's Romanesque Revival courthouse hulks over Union's main intersection. The three-bay facade and five-bay side elevations are delineated by pilasters, and center bays on all four walls project slightly, terminating in gables extending from the shallow hipped roof. The tiny jail, now connected to the building, is at the southeast corner, at the end of a parking lot that someone, perhaps in a fit of exasperation, has labeled “Ainta Street.” The B. F. Smith Fireproof Construction Company of Washington, D.C., remodeled the jail and the record room of the courthouse in 1902.