Hunter v. City of Pittsburgh

Hunter v. Pittsburgh, 207 U.S. 161 (1907), is a landmark case that established the supreme sovereignty of a state over its municipalities.
Background.
In 1906, Pennsylvania passed a law permitting the joining of adjacent municipalities if, during an election regarding the issue, the majority of all votes passed approve the union. Subsequently, the City of Pittsburgh filed in state court to begin the process of an election regarding joining with the City of Allegheny, Pennsylvania. Allegheny pushed back but was turned down in court.
The election was allowed to continue, and a majority of all voters in the two cities combined voted for joining. However, the vast majority of voters in Allegheny voted in opposition, and most of the votes in favor came from Pittsburgh. However, because the majority of the total votes were in favor, the Supreme Court of Pennsylvania ruled the union constitutional under Pennsylvania law. Plaintiffs appealed under the United States Constitution's Contract Clause (Article 1, Section 10, Paragraph 1) and the Due Process Clause of the Fourteenth Amendment.
Decision.
The United States Supreme Court unanimously ruled that the Pennsylvania law violated neither Article I nor the Fourteenth Amendment of the Constitution. Some important lines from the opinion concerning the supremacy of states over the municipalities include the following: