...

In 1921, the right for women to vote freshly obtained, suffragist Alice Paul asked her fellow women’s rights activists whether they wanted to rest on their laurels. The decision at hand, she said, was whether the National Woman’s Party would “furl its banner forever, or whether it shall fling it forth on a new battle front.”

Eventually, Paul and some fellow suffragists chose a new battle: a federal guarantee that the law would treat people equally regardless of their sex. Paul and pacifist lawyer Crystal Eastman, now considered the “founding mother of the ACLU,” drafted the “Lucretia Mott Amendment,” named after the 19th-century women’s rights activist. The original E.R.A. promised, “Men and women shall have equal rights throughout the United States and every place subject to its jurisdiction.”

Paul’s insistence on a constitutional amendment proved to be controversial even in suffragist circles. Paul and other, like-minded activists believed an amendment would be the fastest path to social and economic parity for women, especially because their efforts to implement similar legislation on a state level hadn’t proved successful. But other prominent advocates objected, worried that the E.R.A. went too far and would eliminate hard-won labor protections for women workers. Florence Kelley, a suffragist and labor reformer, accused the N.W.P. of issuing “threats of a sex war.” And, as historian Allison Lange points out in the Washington Post, the N.W.P.’s new direction left behind women of color, who couldn’t exercise their newfound voting rights due to racially biased voter suppression laws.