Question: Who was responsible for a commemorative half dollar struck by the Philadelphia Mint in 1936?
Context: The Lexington-Concord Sesquicentennial half dollar, sometimes the Lexington-Concord half dollar or Patriot half dollar, is a commemorative fifty-cent piece struck by the United States Bureau of the Mint in 1925 in honor of the 150th anniversary of the Battles of Lexington and Concord.  It was designed by Chester Beach. The Connecticut Tercentenary half dollar, sometimes called the Connecticut half dollar, is a commemorative fifty-cent piece struck by the United States Bureau of the Mint in 1935.  The coin was designed by Henry Kreis, and commemorates the 300th anniversary of the founding of Connecticut.  Its obverse depicts the Charter Oak, where according to legend, Connecticut's charter was hidden to save it from the English; an eagle appears on the coin's reverse side. The United States Sesquicentennial coin issue consisted of a commemorative half dollar and quarter eagle (gold $2.50 piece) struck in 1926 at the Philadelphia Mint for the 150th anniversary of American independence.  The obverse of the half dollar features portraits of the first president, George Washington, and the president in 1926, Calvin Coolidge, making it the only American coin to depict a president in his lifetime. Thomas Gatch Melish (October 28, 1876 – February 15, 1948) was a Cincinnati entrepreneur and coin collector.  In the 1930s, Melish was responsible for two United States commemorative coin issues, the Cincinnati Musical Center half dollar and the Cleveland Centennial half dollar. The Hudson, New York, Sesquicentennial half dollar, sometimes called the Hudson Sesquicentennial half dollar, is a commemorative fifty-cent piece struck by the United States Bureau of the Mint in 1935.  The coin was designed by Chester Beach.  Its obverse depicts "Half Moon", flagship of Henry Hudson, after whom the city of Hudson is named. The Cleveland Centennial half dollar is a commemorative United States half dollar struck at the Philadelphia Mint in 1936 and 1937, though all bear the earlier date.  Sometimes known as the Cleveland Centennial Great Lakes Exposition half dollar, it was issued to mark the 100th anniversary of Cleveland, Ohio, as an incorporated city, and in commemoration of the Great Lakes Exposition, held in Cleveland in 1936. The Vermont Sesquicentennial half dollar, sometimes called the Bennington–Vermont half dollar or the Battle of Bennington Sesquicentennial half dollar, is a commemorative fifty-cent piece struck by the United States Bureau of the Mint in 1927.  The coin was designed by Charles Keck, and on its obverse depicts early Vermont leader Ira Allen, brother of Ethan Allen. The Rhode Island Tercentenary half dollar, sometimes called the Providence, Rhode Island Tercentenary half dollar is a commemorative fifty-cent piece struck by the United States Bureau of the Mint in 1936.  The coin was designed by John Howard Benson and Arthur Graham Carey.  Its obverse depicts Roger Williams, founder of Rhode Island.  Although intended to honor the 300th anniversary of the state capital, Providence, no mention of the city appears on the coin. The Cincinnati Musical Center half dollar or Cincinnati Music Center half dollar is a commemorative 50-cent piece struck by the United States Bureau of the Mint in 1936.  Produced with the stated purpose of commemorating the fiftieth anniversary of Cincinnati, Ohio as a center of music, it was conceived by Thomas G. Melish, a coin enthusiast who controlled the group which was allowed to buy the entire issue from the government, and who resold the pieces at high prices. The United States Bicentennial coinage was a set of circulating commemorative coins, consisting of a quarter, half dollar and dollar struck by the United States Mint in 1975 and 1976.  Regardless of when struck, each coin bears the double date 1776–1976 on the normal obverses for the Washington quarter, Kennedy half dollar and Eisenhower dollar.  No coins dated 1975 of any of the three denominations were minted.
Answer: Melish was responsible for two United States commemorative coin issues, the Cincinnati Musical Center half dollar and the Cleveland Centennial half dollar.