Tweed's Case was a landmark decision by the United States Supreme Court in 1872. The case involved William M. Tweed, a prominent New York City politician who was accused of fraud and corruption. Tweed was charged with misappropriating public funds and was convicted in a state court. He appealed his conviction to the Supreme Court, arguing that the state court had violated his rights under the Fourteenth Amendment. The Supreme Court ruled in favor of Tweed, holding that the state court had violated his rights under the Fourteenth Amendment. The Court held that the state court had failed to provide Tweed with due process of law, as required by the Fourteenth Amendment. The Court also held that the state court had failed to provide Tweed with a fair trial, as required by the Fourteenth Amendment. The decision in Tweed's Case was significant because it established the principle that the Fourteenth Amendment protects individuals from state court proceedings that violate their rights. This decision has been cited in numerous cases since then, and it remains an important precedent in the area of constitutional law.

In Tweed's Case, the Supreme Court was asked to decide whether a New York City law that allowed for the appointment of commissioners to oversee public works projects and set salaries violated the Constitution. The majority opinion held that it did not violate any constitutional provisions because it was within the scope of state authority. However, in his dissenting opinion Justice Field argued that this law gave too much power to local officials and could lead to corruption or favoritism in awarding contracts. He further argued that such an act should be subject to congressional approval before being enacted into law as it had implications beyond just one city or state. Field also believed there were other ways for cities like New York City to finance their public works projects without having so much control over them vested with local authorities who may have conflicts of interest when making decisions about how funds are allocated and spent on these projects.