Harry L. Earle and Lewis A. Walker were granted the first patent for the zipper in 1912, called the "Automatic Continuous Clothing Closure". Gideon Sundback further improved the design in 1913 with his "Hookless Fastener" which replaced hook-and-eye closures and changed zippers forever. Zippers became popular in clothing in the 1930s as a fashionable addition and after World War II as zippers represented cultural rebellion and new values for younger generations, gaining worldwide popularity in the United States, Japan, and Germany while also being highly profitable.