John R. Sinnock was an American engraver and coin designer, best known for his work with the United States Mint. He was born on March 24, 1890, and became prominent for designing the reverse of the Franklin half dollar, which features a depiction of the Liberty Bell. Sinnock also created the design for the Washington quarter in 1932, commemorating the 200th anniversary of George Washington's birth. His contributions to numismatics have left a lasting impact, and his designs continue to be recognized and appreciated by collectors and historians alike.