Davenport City v. Dows was a case heard by the United States Supreme Court in 1872. The case involved a dispute between the City of Davenport, Iowa and a man named William Dows. Dows had been granted a patent for a bridge over the Mississippi River in 1856. The City of Davenport had built a bridge over the river in 1868, which was similar to Dows' bridge. Dows sued the city for patent infringement, claiming that the city had used his patented design without his permission. The Supreme Court ruled in favor of Dows, finding that the city had indeed infringed on his patent. The Court held that the city was liable for damages, and that Dows was entitled to compensation for the use of his patented design. The Court also held that the city was not entitled to any profits from the bridge, as it had not obtained a license from Dows to use his design. This case established the principle that patent holders are entitled to compensation for the unauthorized use of their patented designs.

In Davenport City v. Dows, the Supreme Court was asked to decide whether a city ordinance that prohibited the sale of alcohol within two miles of any schoolhouse was constitutional. The majority opinion held that it was not unconstitutional and upheld the ordinance. However, Justice Field dissented from this decision and argued that such an ordinance violated both state law and individual rights under the Fourteenth Amendment's Due Process Clause. He reasoned that while states have broad authority to regulate public health, safety, morals, and welfare through their police powers; they cannot do so in a way which violates fundamental rights or interferes with existing laws passed by other branches of government without due process of law. Furthermore, he argued that prohibiting liquor sales within two miles of any schoolhouse went beyond what is necessary for protecting public health or morality as there were already numerous laws on the books regulating alcohol consumption in Iowa at this time. Thus he concluded that such an overly restrictive regulation could not be justified under either state or federal law nor did it serve any legitimate purpose related to public safety or morality