Ex Parte Milwaukie and Minnesota Railroad Company was a case heard by the United States Supreme Court in 1864. The railroad company had been ordered to pay damages for obstructing navigation on the St. Croix River, but argued that it should not be held liable because its actions were authorized by Congress. The court ruled against the railroad company, finding that although Congress could authorize such activities, they must still comply with state laws governing navigable waters. Furthermore, any damage caused as a result of their activities would have to be paid for regardless of congressional authorization or approval. This decision established an important precedent regarding federal-state relations and clarified how far Congressional authority extends when it comes to matters concerning navigable waterways within states’ borders.

In Ex Parte Milwaukie and Minnesota Railroad Company, the Supreme Court was asked to decide whether a state court had jurisdiction over a case involving an interstate railroad. The majority opinion held that the state court did have such jurisdiction. However, Justice Field dissented from this decision on two grounds: firstly, he argued that Congress had exclusive authority to regulate commerce between states; secondly, he contended that allowing individual states to exercise control over interstate railroads would lead to conflicting regulations and ultimately impede free trade among the states. In conclusion, Justice Field believed that only Congress should be allowed to regulate interstate commerce in order for it remain free of interference by individual states.