The Equal Rights Amendment, which would prohibit discrimination based on gender, was sent to the states for ratification in 1972. Congress set a deadline of 1979 for three-quarters of state legislatures to ratify the amendment, then extended it to 1982.

President Biden’s remarks were largely a symbolic gesture of support for a century-long campaign to enshrine gender equality into the Constitution. But advocates said they could add heft to a future legal fight.