Rees v. City of Watertown was a United States Supreme Court case that addressed the issue of whether a municipality could be held liable for damages caused by a defective bridge. The plaintiff, Rees, was injured when his horse and wagon fell through a bridge owned by the City of Watertown. Rees sued the city for damages, arguing that the city was negligent in maintaining the bridge. The Supreme Court held that the city could be held liable for damages caused by the defective bridge. The Court reasoned that the city had a duty to maintain the bridge in a safe condition, and that it had breached that duty by failing to do so. The Court also noted that the city had received notice of the bridge's condition prior to the accident, and had failed to take any action to repair it. The Court concluded that the city was liable for the damages caused by the defective bridge, and that Rees was entitled to recover damages from the city. This case established the principle that municipalities can be held liable for damages caused by their negligence in maintaining public infrastructure.

Justice Field delivered the dissenting opinion in Rees v. City of Watertown, arguing that the city had acted within its rights when it issued bonds to finance a railroad project. He argued that while Congress has exclusive authority over interstate commerce, states have concurrent power to regulate intrastate commerce and may use their police powers for this purpose. In his view, the city's action was an exercise of its police power and did not interfere with any federal law or regulation; therefore, he concluded that it should be upheld as constitutional. Furthermore, Justice Field noted that if cities were prohibited from issuing such bonds then they would be unable to develop public works projects which could benefit both citizens and businesses alike - something which is essential for economic growth and development in a state or municipality. Thus he concluded by saying "the right of local self-government must remain unimpaired."