The Suffolk County case was a landmark decision by the United States Supreme Court in 1869. The case involved a dispute between the Suffolk County Board of Supervisors and the Boston and Providence Railroad Company. The Board of Supervisors had passed a law that prohibited the railroad from running its trains through the county at night. The railroad argued that the law was unconstitutional because it violated the Commerce Clause of the United States Constitution. The Supreme Court agreed with the railroad and held that the law was unconstitutional. The Court reasoned that the law interfered with interstate commerce and was therefore invalid. The decision was significant because it established the principle that states cannot pass laws that interfere with interstate commerce. This principle has been applied in numerous cases since then and has been an important part of the development of the American legal system.

In the dissenting opinion of The Suffolk County case, Justice Field argued that Congress did not have the power to pass a law which would allow for an individual's right to sue in federal court. He argued that this was a matter of state jurisdiction and should be left up to each state's legislature. Furthermore, he noted that if Congress had such authority it could potentially lead to other laws being passed which would interfere with states' rights and powers. He also stated that allowing individuals access to federal courts could create an imbalance between those who can afford legal representation and those who cannot as well as creating unnecessary delays in resolving cases due to overcrowding in the courts. Ultimately, Justice Field concluded by stating his belief that Congress does not possess the power or authority necessary for passing such legislation and thus any attempt at doing so is unconstitutional.