The Fleming v. Fleming case in 1923 revolved around a dispute over the will of Mrs. Mary E. Fleming, who left her estate to her husband and children from a previous marriage. The Supreme Court had to determine whether or not the law of Kentucky - where Mrs. Fleming resided at the time of death - should govern the distribution of her personal property located in Illinois, or if Illinois law should apply instead. The court ruled that although generally, a person's domicile state laws govern their personal property disposition upon death (lex domicilii), there are exceptions when it comes to real estate properties which follow local jurisdiction rules (lex situs). However, since this case involved personal property and not real estate, they applied lex domicilii principle and decided that Kentucky law would prevail. This decision was significant as it clarified how interstate succession laws work for different types of assets: while real estates follow local jurisdiction rules (wherever they're situated), movable properties adhere to decedent’s domicile state laws.

The dissenting opinion in the case of Fleming et al. v. Fleming argued that the majority's decision to uphold a lower court ruling, which allowed for the termination of a trust established by a father for his son, was incorrect and inconsistent with previous rulings on similar matters. The dissenting justices believed that there were no grounds to terminate this trust as it did not violate any laws or public policy at its inception nor during its operation. They also pointed out that the beneficiary had willingly accepted benefits from this trust before seeking its termination, which they saw as an implicit acceptance of all terms set forth by his father when establishing it. Furthermore, they disagreed with the majority’s interpretation of “restraint on alienation” clause within trusts law and felt their colleagues’ decision could potentially disrupt future cases involving such clauses.