This Hershey's chocolate cups filled with peanut butter began in 1928 by H. B. Reese.  He was working for the Hershey's company then but developed this candy in his basement.  It was so successful he went out on his own.  When he passed away in May 16, 1956 he left his company to his sons who amalgamated with the Hershey company in 1963.  It is the Hershey company's top seller.