1893 - Colorado becomes first state to grant women the right to vote.

1920 - The 19th Amendment to the U.S. Constitution is passed, granting women the right to vote.

1963 - Congress passes the Equal Pay Act is a federal law requiring that employers pay all employees equally for equal work, regardless of whether the employees are male or female.

1964 - The Civil Rights Act of 1964 passes Congress, prohibiting gender discrimination in a number of settings -- including voting, public facilities, public education, and employment.

1971 - The Equal Rights Amendment passes Congress, intended to explicitly guarantee equality to all persons, regardless of gender. The proposed amendment to the U.S. Constitution did not receive enough votes for ratification by the individual states, and was never signed into law.

1978 - The Pregnancy Discrimination Act is signed, prohibiting employment discrimination against female workers who are (or intend to become) pregnant -- including discrimination in hiring, failure to promote, and wrongful termination.

1993 - The Family and Medical Leave Act (FMLA) is passed, giving employees the right to take time off from work in order to care for a newborn (or recently adopted) child, or to look after an ill family member.