In Taylor vs. Morton, the Supreme Court ruled that a slave owner could not reclaim his runaway slaves in another state if they had been emancipated by the laws of that state. The case began when John Taylor sued William Morton for possession of two escaped slaves who had been living in Ohio since 1854. Ohio law prohibited slavery and declared any person born after July 4th, 1803 to be free upon reaching adulthood. Therefore, even though the two men were legally owned by Taylor at one point, he was not entitled to their return because they were now considered free under Ohio law. This ruling established an important precedent which protected those escaping from slavery and ensured that states would recognize each other's emancipation laws regardless of where a former slave might have fled to seek freedom.

In Taylor v. Morton, the Supreme Court was asked to decide whether a slave named Rachel had been legally emancipated by her former owner, Thomas Jefferson Taylor. The majority opinion held that she had not been legally freed and must remain in slavery. However, Justice Nelson dissented from this decision and argued that Rachel should be declared free because of the circumstances surrounding her emancipation. He reasoned that since there was no dispute as to who owned Rachel or what rights were granted upon emancipation, it would be unjust for the court to deny her freedom when all parties involved agreed on those facts. Furthermore, he noted that if slaves could not rely on their owners’ promises of freedom then they would have no incentive whatsoever to obey them or perform any labor at all; thus making slavery an unenforceable institution altogether. In conclusion, Justice Nelson believed that justice demanded recognition of Rachel's right to liberty under these particular circumstances and urged his colleagues in dissent to grant it accordingly