Equal Pay Act of 1963
In 1942, Republican congresswoman Winifred C. Stanley from Buffalo, N.Y. introduced H.R. 5056, Prohibiting Discrimination in Pay on Account of Sex, which did not pass at the time. The issue languished until 10 June 1963, when Congress passed the Equal Pay Act ("EPA" or the "Act") as an amendment to the Fair Labor Standards Act, to "prohibit discrimination on account of sex in the payment of wages by employers."
Equal pay for equal work
2018 Update
"Law on Equal Pay Certification based on the Equal Pay Standard in Iceland"