Robbins v. Chicago City was a United States Supreme Court case that was decided in 1866. The case involved a dispute between the City of Chicago and a man named John Robbins. Robbins had purchased a piece of property in the city and had been granted a permit to build a house on the property. However, the city had passed an ordinance that prohibited the construction of any building on the property. Robbins argued that the ordinance was unconstitutional and that he should be allowed to build his house. The Supreme Court ruled in favor of Robbins, finding that the ordinance was unconstitutional. The Court held that the ordinance violated the due process clause of the Fourteenth Amendment, which states that no state shall “deprive any person of life, liberty, or property, without due process of law.” The Court also held that the ordinance was an unreasonable exercise of the city’s police power, which is the power of the government to regulate activities for the public good. The decision in Robbins v. Chicago City was an important one, as it established the principle that the government cannot pass laws that are arbitrary or unreasonable. This decision has been cited in numerous cases since then, and it has been used to protect the rights of individuals from government overreach.

In the case of Robbins v. Chicago City, the Supreme Court was asked to consider whether a city ordinance that prohibited certain types of business activities within its limits violated the Constitution. The majority opinion held that it did not violate any constitutional rights and upheld the ordinance as valid. However, Justice Field dissented from this decision, arguing that while cities have broad powers to regulate their internal affairs, they cannot pass laws which interfere with private property or contract rights without due process of law. He argued further that in this particular instance there had been no showing by Chicago City officials as to why such an ordinance was necessary for public safety or welfare and thus could not be justified under existing legal principles. In conclusion he stated his belief that "the power assumed by [Chicago] is one which does not belong to them."