The Isabella quarter or Columbian Exposition quarter was a United States commemorative coin struck in 1893. Congress authorized the piece at the request of the Board of Lady Managers of the World's Columbian Exposition. The quarter depicts the Spanish queen Isabella I of Castile, who sponsored Columbus's voyages to the New World. It was designed by Bureau of the Mint Chief Engraver Charles E. Barber, and is the only U.S. commemorative of that denomination that was not intended for circulation.