The half union (separate varieties known as J-1546 through J-1549) was a United States pattern coin with a face value of fifty U.S. Dollars. It is often thought of as one of the most significant and well-known patterns in the history of the U.S. Mint. The basic design, featuring Liberty on the obverse, was slightly modified from the similar $20 "Liberty Head" Double Eagle, which was designed by James B. Longacre and minted from 1849 to 1907. Some half unions can have a somewhat smaller or larger head than others.