Law vs. Cross was a case heard by the United States Supreme Court in 1861 that dealt with the issue of whether or not an individual could be held liable for damages caused to another person's property due to negligence. The plaintiff, Law, had sued Cross after his horse and wagon were damaged when they collided with a tree on Cross' land. Law argued that he should be compensated for his losses because it was negligent of Cross to have left the tree standing without taking any precautions against potential damage from its presence. The court ultimately ruled in favor of Law, finding that since there had been no warning signs posted about the danger posed by the tree and no other preventative measures taken, then it was reasonable for him to assume that such risks did not exist on this particular piece of land and therefore he should receive compensation from Cross for his losses incurred as a result of their collision with said tree.

In Law v. Cross, the Supreme Court of the United States was asked to decide whether a state court had jurisdiction over a case involving citizens from different states. The majority opinion held that it did not have such jurisdiction and dismissed the case. However, Justice Grier dissented from this ruling on two grounds: firstly, he argued that Congress had given state courts concurrent jurisdiction in cases between citizens of different states; secondly, he noted that there were no federal laws or treaties which prohibited such suits being heard by state courts. He concluded by stating his belief that if Congress intended to limit these rights then they should do so explicitly rather than leaving it up to judicial interpretation.