Pompton v. Cooper Union was a case heard by the United States Supreme Court in 1879. The case involved a dispute between the Pompton Paper Company and the Cooper Union for the Advancement of Science and Art. The Pompton Paper Company had leased a building from the Cooper Union and had made improvements to the building. When the lease expired, the Pompton Paper Company refused to vacate the premises and the Cooper Union sued for possession. The Supreme Court held that the Pompton Paper Company was not entitled to compensation for the improvements it had made to the building. The Court reasoned that the improvements were made to the building with the knowledge that the lease would eventually expire and that the Pompton Paper Company had no right to expect compensation for the improvements. The Court also held that the Pompton Paper Company was not entitled to damages for the loss of its business as a result of the eviction. The Court reasoned that the Pompton Paper Company had no right to expect that the lease would be extended and that the Cooper Union had acted within its rights in evicting the Pompton Paper Company. In conclusion, the Supreme Court held that the Pompton Paper Company was not entitled to compensation for the improvements it had made to the building or damages for the loss of its business as a result of the eviction. The Court reasoned that the Pompton Paper Company had no right to expect that the lease would be extended and that the Cooper Union had acted within its rights in evicting the Pompton Paper Company.

Justice Field delivered the dissenting opinion in POMPTON v. COOPER UNION, arguing that the majority's decision was wrongfully decided and should be reversed. He argued that Cooper Union had no right to take possession of Pompton's land without due process of law, as it had done by entering onto the property and erecting a fence around it. Furthermore, he noted that even if Cooper Union did have such a right under New York law (which he doubted), they still could not do so without compensating Pompton for his loss; this is because taking away someone else's property is an act which requires compensation regardless of any state laws or regulations governing its use. Finally, Justice Field asserted that since there was no evidence presented at trial showing any agreement between Pompton and Cooper Union regarding ownership or usage rights over the disputed land, then Cooper Union must pay damages to compensate for their trespass on Pompton’s property.