Three years after women won the right to vote, the Equal Right Amendment (ERA) was introduced in Congress by Senator Charles Curtis Curtis and Representative Daniel Read Anthony Jr., both Republicans. This amendment stated that civil rights cannot be denied on the basis of one's sex. It was authored by Alice Paul, head of the National Women's Party, who led the suffrage campaign. Through the efforts of Alice Paul, the Amendment was introduced into each session of the United States Congress, but it was buried in committee in both Houses of Congress. In 1946, it was narrowly defeated by the full Senate, 38–35. In February 1970, twenty NOW leaders disrupted the hearings of the U.S. Senate Subcommittee on Constitutional Amendments, demanding the ERA be heard by the full Congress. In May of that year, the Senate Subcommittee began hearings on the ERA under Senator Birch Bayh. In June, the ERA finally left the House Judiciary Committee due to a discharge petition filed by Representative Martha Griffiths. In March 1972, the ERA was approved by the full Senate without changes, 84–8. Senator Sam Ervin and Representative Emanuel Celler succeeded in setting a time limit of seven years for ratification. The ERA then went to the individual states for approval but failed to win in enough of them (38) to become law. In 1978, Congress passed a disputed (less than supermajority) three year extension on the original seven year ratification limit, but the ERA could not gain approval by the needed number of states.