Blake v. San Francisco is a United States Supreme Court case that was decided in 1885. The case involved a dispute between the City of San Francisco and the Blake Estate over the ownership of a piece of land. The City of San Francisco had granted a franchise to the Blake Estate to build a street railway on the land in question. The City then attempted to revoke the franchise, claiming that the land was part of a public park. The Blake Estate argued that the franchise was a contract and that the City had no right to revoke it. The Supreme Court ruled in favor of the Blake Estate, holding that the franchise was a contract and that the City had no right to revoke it. The Court also held that the City had no right to take the land for public use without just compensation. The Court further held that the City had no right to revoke the franchise without providing just compensation to the Blake Estate. This case established the principle that the government cannot take private property for public use without providing just compensation.

In Blake v. San Francisco, the Supreme Court was asked to decide whether a city ordinance that required businesses to pay an annual license fee for the privilege of operating within its limits violated the Fourteenth Amendment’s Equal Protection Clause. The majority opinion held that it did not violate equal protection because there was no evidence of discrimination against any particular class or group and thus concluded that it could be enforced as written. Justice Field dissented from this conclusion, arguing instead that such ordinances were inherently unequal in their application since they placed a greater burden on smaller businesses than larger ones due to their fixed nature; he further argued that these ordinances should only be allowed if they are applied uniformly across all business sizes and types regardless of size or type. In his view, this would ensure fairness among all those affected by them and prevent arbitrary enforcement which could lead to unfairness in taxation practices between different classes or groups of people.