Prior to 1971, laws in the United States regularly discriminated on the basis of sex. During this time, the Supreme Court upheld laws that barred women from practicing law, Bradwell v. The State of Illinois, 83 U.S. (16 Wall.) 130 (1872), enacted a minimum wage for women only, Muller v. Oregon, 208 U.S. 412, 422–423 (1908)(1908), prohibited women from working in restaurants at night, Radice v. New York, 264 U.S. 292 (1924), prevented licensing women as bartenders, Goesaert v. Cleary, 335 U.S. 464 (1948), and excepted women from obligatory jury duty, Hoyt v. Florida, 368 U.S. 57 (1961).
In some of these cases, the Supreme Court used language suggesting a level of scrutiny resembling rational basis review. The Radice Court justified a law barring women from working at night stating that "since we are unable to say that the finding is clearly unfounded, we are precluded from reviewing the legislative determination." 264 U.S. at 294–295. Referring to differences between the sexes, the Radice Court continues that "[t]his difference justifies a difference in legislation and upholds that which is designed to compensate for some of the burdens which rest upon her." 264 U.S. at 295 (quoting Muller). The Goesaert Court upheld a law barring women from tending bars by stating that "since the line they have drawn is not without a basis in reason, we cannot give ear to the suggestion that the real impulse behind this legislation was an unchivalrous desire of male bartenders to try to monopolize the calling." 335 U.S. at 467.
In 1971, for the first time, the Supreme Court invalidated a law that discriminated based on sex. Reed v. Reed, 404 U.S. 71 (1971). In Reed, a law that gave preference to men over women in the administration of estates, was challenged under the Equal Protections Clause of the Fourteenth Amendment. The Reed Court claimed it was applying rational basis as the standard of review: "The question presented by this case, then, is whether a difference in the sex of competing applicants for letters of administration bears a rational relationship to a state objective that is sought to be advanced". 404 U.S. at 76. The Reed Court held that the government's interest in "reducing the workload on probate courts by eliminating one class of contests is not without some legitimacy." Id. However, the relationship between this interest and the government's action was declared"the very kind of arbitrary legislative choice forbidden by the Equal Protection Clause of the Fourteenth Amendment". Id.
The Reed Court did not announce that gender is, or might be, treated as a suspect classification. Shortly after Reed, in Frontiero v. Richardson, the Supreme Court declared that sex-based classification should be held to strict scrutiny; however there was no majority opinion and so the issue remained open. 411 U.S. 677 (1973). Three years later, Reed was interpreted by a majorityas declaring gender a suspect classification subject to intermediate scrutiny. Craig v. Boren, 429 U.S. 190, 197 (1976). Since Craig, issues surrounding scrutiny of sex-based discrimination have become more nuanced. See United States v. Virginia, 518 U.S. 515 (1996) (declaring that governmental gender-based government action must demonstrate exceedingly persuasive justification).
Conclusion: Reed signaled a crack in the Supreme Court's tendency to uphold governmental gender discrimination and marked a pivot in the way the Court would apply Equal Protection to the classification of sex. Reed was a case in which gender equality got its foot in the door.