What constitutional clause was central to the ruling in Fletcher v. Peck?

The ruling in Fletcher v. Peck centered on the Contract Clause, which is found in Article I, Section 10 of the United States Constitution. This clause prohibits states from passing any law that impairs the obligation of contracts. In this case, the Supreme Court held that the Georgia legislature had violated the Contract Clause by invalidating a land grant that had been made to a private party. The Court determined that once the land grant was made, it constituted a valid contract, and thus, the state had no authority to rescind it. This decision was significant as it established a precedent for the protection of contracts against state interference, reinforcing the principle of contract rights in the United States legal system and expanding the role of the federal judiciary in reviewing state legislation.