United States Treasury Building (19th-century federal architecture)

Constructed in phases during the 19th century, with major work beginning in the 1830s and continuing through the 1860s, the United States Treasury Building is one of Washington’s oldest federal departmental buildings. Early design work involved architect Robert Mills and subsequent 19th-century additions created a complex of interconnected wings and neoclassical façades. The building’s colonnades, ornamented cornices, and monumental massing reflect federal architectural trends of the period while it has continuously served as headquarters for the U.S. Department of the Treasury.