On March 22, by a vote of 84 to 8, the Senate passed the Equal Rights Amendment, a goal of feminists for half a century. Since the House had given equally lopsided approval the previous fall, the amendment went to the states for ratification. Thirty-two minutes after the Senate vote, Hawaii became the first to ratify; New Hampshire and Nebraska followed the next day. Support for the idea of equality quickly swept the country, with both major parties endorsing the amendment. Within a year of the Senate vote, 30 of the required 38 states had passed the E.R.A. Boosters confidently predicted a quick completion of the process.

Over the remainder of 1973, though, no more states added their names to the list. In 1974, even as polls showed three-quarters of Americans in favor, just three states gave their consent. One state ratified in 1975 and one in 1977, raising the total to 35, but that was all.The E.R.A.’s time limit expired in 1982, and since then, there has been no serious attempt to get it through Congress again. What happened?

Most likely, Americans took a second look at the E.R.A. and did not like what they saw. Some, especially in the South, feared a loss of women’s “special role” in the family. But others, including many who sympathized with the women’s movement, were uneasy over what the Supreme Court might make of the amendment’s bare reference to “equality of rights.” When opponents raised specters of unisex bathrooms, women being drafted, and a ban on alimony, supporters responded with little but blandishments or mockery.

Even as the amendment faltered, though, legal and social barriers continued to fall. Women won public office in ever-growing numbers, attended the service academies, and entered virtually every profession. As these changes took root, many citizens wondered if the blunderbuss E.R.A. was the best way to resolve a very complicated set of questions.

Women’s rights had been broadly protected in the 1964 Civil Rights Act, and during the 1970s additional measures extended the principle to such areas as maternity leave. One strongly feminist scholar admits that “by the time of its defeat, it is not clear what practical effect the E.R.A. might have had.” As the battle for equality shifted from the legal to the social arena, the E.R.A. came to look redundant where it overlapped with existing laws, and like a can of worms where it did not. In the end, feminist victories in other areas made the E.R.A. seem irrelevant. Its overwhelming early support gave striking proof of the strength of the women’s movement, and its later defeat, paradoxically, showed how successful the movement had already been.