Bradwell v. State of Illinois (1872):

It certainly cannot be affirmed, as an historical fact, that this has ever been established as one of the fundamental privileges and immunities of the sex. On the contrary, the civil law, as well as nature herself, has always recognized a wide difference in the respective spheres and destinies of man and woman. Man is, or should be, woman's protector and defender. The natural and proper timidity and delicacy which belongs to the female sex evidently unfits it for many of the occupations of civil life. The Constitution of the family organization, which is founded in the divine ordinance as well as in the nature of things, indicates the domestic sphere as that which properly belongs to the domain and functions of womanhood. The harmony, not to say identity, of interest and views which belong, or should belong, to the family institution is repugnant to the idea of a woman adopting a distinct and independent career from that of her husband. So firmly fixed was this sentiment in the founders of the common law that it became a maxim of that system of jurisprudence that a woman had no legal existence separate from her husband, who was regarded as her head and representative in the social state, and, notwithstanding some recent modifications of this civil status, many of the special rules of law flowing from and dependent upon this cardinal principle still exist in full force in most states. One of these is that a married woman is incapable, without her husband's consent, of making contracts which shall be binding on her or him. This very incapacity was one circumstance which the Supreme Court of Illinois deemed important in rendering a married woman incompetent fully to perform the duties and trusts that belong to the office of an attorney and counselor.

It is true that many women are unmarried and not affected by any of the duties, complications, and incapacities arising out of the married state, but these are exceptions to the general rule. The paramount destiny and mission of woman are to fulfill the noble and benign offices of wife and mother. This is the law of the Creator. And the rules of civil society must be adapted to the general constitution of things, and cannot be based upon exceptional cases.

Muller v. Oregon (1908):

That woman's physical structure and the performance of maternal functions place her at a disadvantage in the struggle for subsistence is obvious. This is especially true when the burdens of motherhood are upon her. Even when they are not, by abundant testimony of the medical fraternity, continuance for a long time on her feet at work, repeating this from day to day, tends to injurious effects upon the body, and, as healthy mothers are essential to vigorous offspring, the physical wellbeing of woman becomes an object of public interest and care in order to preserve the strength and vigor of the race.

Still again, history discloses the fact that woman has always been dependent upon man. He established his control at the outset by superior physical strength, and this control in various forms, with diminishing intensity, has continued to the present. As minors, though not to the same extent, she has been looked upon in the courts as needing especial care that her rights may be preserved.

Goesaert v. Cleary (1948):

Since bartending by women may, in the allowable legislative judgment, give rise to moral and social problems against which it may devise preventive measures, the legislature need not go to the full length of prohibition if it believes that, as to a defined group of females, other factors are operating which either eliminate or reduce the moral and social problems otherwise calling for prohibition. Michigan evidently believes that the oversight assured through ownership of a bar by a barmaid's husband or father minimizes hazards that may confront a barmaid without such protecting oversight. This Court is certainly not in a position to gainsay such belief by the Michigan legislature. If it is entertainable, as we think it is, Michigan has not violated its duty to afford equal protection of its laws. We cannot cross-examine, either actually or argumentatively, the mind of Michigan legislators, nor question their motives. 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.

Hoyt v. Florida (1961):
 
Despite the enlightened emancipation of women from the restrictions and protections of bygone years, and their entry into many parts of community life formerly considered to be reserved to men, woman is still regarded as the center of home and family life. We cannot say that it is constitutionally impermissible for a State, acting in pursuit of the general welfare, to conclude that a woman should be relieved from the civic duty of jury service unless she herself determines that such service is consistent with her own special responsibilities.

Florida is not alone in so concluding. Women are now eligible for jury service in all but three States of the Union. Of the forty-seven States where women are eligible, seventeen besides Florida, as well as the District of Columbia, have accorded women an absolute exemption based solely on their sex, exercisable in one form or another.”

Reed v. Reed (1971):

To give a mandatory preference to members of either sex over members of the other, merely to accomplish the elimination of hearings on the merits, is to make the very kind of arbitrary legislative choice forbidden by the Equal Protection Clause of the Fourteenth Amendment; and whatever may be said as to the positive values of avoiding intrafamily controversy, the choice in this context may not lawfully be mandated solely on the basis of sex. . . .

By providing dissimilar treatment for men and women who are thus similarly situated, the challenged section violates the Equal Protection Clause.