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The Monroe Doctrine Centennial half dollar was a fifty-cent piece struck by the United States Bureau of the Mint. Bearing portraits of former U.S. Presidents James Monroe and John Quincy Adams, the coin was issued in commemoration of the centennial of the Monroe Doctrine and was produced at the San Francisco Mint in 1923. Sculptor Chester Beach is credited with the design, although the reverse closely resembles an earlier work by Raphael Beck.