In the case of Labine v. Vincent, 1970, the U.S. Supreme Court ruled in favor of Louisiana's inheritance laws that allowed illegitimate children to be excluded from their biological father's estate if he died without a will (intestate). The plaintiff was an illegitimate child who challenged this law after being denied her share of her deceased father’s property because it had been distributed among his legitimate heirs according to state law. She argued that this violated the Equal Protection Clause of the Fourteenth Amendment as she was discriminated against based on her status as an illegitimate child. However, the court upheld Louisiana's statute with a majority vote stating that states have broad power over matters related to family and family-property arrangements and there is no constitutional requirement for treating all children alike under such circumstances.

In the dissenting opinion for Labine v. Vincent, Justice William O. Douglas argued that Louisiana's law allowing illegitimate children to inherit from their mothers but not their fathers was unconstitutional because it violated the Equal Protection Clause of the Fourteenth Amendment. He contended that this law unfairly discriminated against illegitimate children based on circumstances beyond their control and perpetuated societal prejudices against them. Furthermore, he disagreed with the majority's assertion that there were valid reasons for treating legitimate and illegitimate children differently in inheritance laws, such as maintaining family stability or encouraging marital relationships. Instead, he believed these justifications were outdated and did not reflect modern understanding of familial relationships or child development.