In the 1967 case of Glona v. American Guarantee & Liability Insurance Co., a mother sued for damages following the wrongful death of her illegitimate son in Louisiana. The state law at that time did not allow parents to recover damages for the wrongful death of an illegitimate child, but it allowed recovery if the child was legitimate. The Supreme Court ruled this distinction unconstitutional under Equal Protection Clause of Fourteenth Amendment, stating that denying a parent's right to sue due to their child's illegitimacy is unjustifiable and discriminatory. This ruling established precedent by extending equal protection rights beyond racial discrimination cases into other areas such as family relationships and legitimacy status.

In the dissenting opinion for Glona v. American Guarantee & Liability Insurance Co., Justice Harlan argued that the majority's decision was a departure from established principles of federalism and judicial restraint. He contended that it was not within the Supreme Court's purview to decide on matters of state law, such as wrongful death statutes, unless there is clear violation of constitutional rights. In this case, he believed Louisiana’s statute denying recovery by parents for the wrongful death of an illegitimate child did not violate equal protection clause since it treated all parents (of legitimate or illegitimate children) equally in their inability to recover damages if they had failed to legitimize their offspring under state law. Furthermore, he pointed out that no other court had found similar laws unconstitutional and warned against unwarranted intrusion into areas traditionally left to states' discretion.