What is on the Back of the Half Dollar?

By GovMint :

The back, or reverse, of the current Kennedy Half Dollar, features the Presidential Seal. This design has been a staple since the introduction of this series in 1964 and showcases a heraldic eagle carrying a shield on its chest. Above the eagle is a ring of stars that represents the original 13 colonies along with the national motto, "E Pluribus Unum."

Prior to the Kennedy Half Dollar, the Franklin Half Dollar was issued from 1948 to 1963. The reverse of the Franklin Half Dollar features the iconic Liberty Bell alongside an eagle.

Sources Used:

 https://www.usmint.gov/coins/coin-medal-programs/circulating-coins/half-dollar