Loan Association v. Topeka was a United States Supreme Court case that addressed the issue of whether a state could tax a national bank. The case was brought by the Loan Association of Topeka, Kansas, which argued that the state of Kansas had no authority to tax a national bank. The Supreme Court agreed with the Loan Association, ruling that the state of Kansas had no authority to tax a national bank. The Court reasoned that the power to tax a national bank was reserved to the federal government, and that the state of Kansas had no authority to interfere with the federal government's power. The Court also held that the state of Kansas had no authority to interfere with the federal government's power to regulate national banks. The Court's decision was a victory for the Loan Association, as it prevented the state of Kansas from taxing a national bank. The decision also established the principle that the federal government has exclusive authority to regulate and tax national banks.

In Loan Association v. Topeka, the Supreme Court was asked to decide whether a state law that allowed cities to issue bonds for public works projects violated the Contract Clause of the United States Constitution. The majority opinion held that it did not violate this clause and upheld the law. Justice Field wrote a dissenting opinion in which he argued that such laws were unconstitutional because they impaired existing contracts between private parties and their creditors by allowing municipalities to borrow money at lower interest rates than those offered by private lenders. He noted that while states have broad powers over municipal affairs, these powers are limited when it comes to interfering with contractual obligations already made between individuals or corporations and their creditors. Therefore, he concluded, any attempt by a state legislature to interfere with such contracts should be declared void as being contrary to both federal and state constitutions.