Township of Rock Creek v. Strong is a United States Supreme Court case that was decided in 1877. The case involved a dispute between the Township of Rock Creek and the Strong family over the ownership of a piece of land. The Strong family had purchased the land from the township in 1867, but the township later attempted to reclaim the land, claiming that the sale was invalid. The Supreme Court ruled in favor of the Strong family, finding that the township had no legal right to reclaim the land. The Court held that the township had no authority to sell the land in the first place, as it was not authorized to do so by the state legislature. Furthermore, the Court found that the Strong family had acted in good faith when they purchased the land, and that they had a valid title to the property. The Court's decision in Township of Rock Creek v. Strong established the principle that a municipality cannot sell land without the proper authority from the state legislature. It also established that a purchaser of land from a municipality is entitled to a valid title to the property, even if the municipality later attempts to reclaim the land.

In Township of Rock Creek v. Strong, the United States Supreme Court was tasked with determining whether a township had the authority to levy taxes on land that it did not own but which was located within its boundaries. The majority opinion held that such taxation was unconstitutional and violated the Fourteenth Amendment's Due Process Clause. However, in dissent Justice Field argued that while he agreed with much of what had been said by his colleagues, he believed there were certain circumstances where a municipality could constitutionally tax property outside its jurisdiction if it provided some benefit or service to those properties. He further noted that this power should be limited only when necessary for public safety or welfare and should never be used as an instrument of oppression against citizens living beyond municipal borders.