O. Henry Hall, a historic downtown building located at 601 Colorado Street, originally opened in 1881 as a federal courthouse and post office. Designed by architect James G. Hill, its construction was overseen by famed antebellum-era master builder Abner Cook, whose best-known work is probably the Texas Governor's Mansion. The structure's Renaissance Revival-style architecture makes it noteworthy among the institutional buildings of the era, according to the inscription of its historical marker:
Architecturally, the building . . .
