"building where U.S. Congress meets," 1793 (in writings of Thomas Jefferson), from L. Capitolium
, temple of Jupiter Optimus Maximus on the Capitoline Hill in ancient Rome. Used earlier of Virginia state houses (1699). Its use in American public architecture deliberately evokes Roman republican imagery. With reference to the Roman citadel, it is recorded from late 14c. Relationship to capital
is likely but not certain.