Bank v. Lanier was a United States Supreme Court case that was decided in 1870. The case involved a dispute between the Bank of the United States and Lanier, a former employee of the bank. The bank had sued Lanier for breach of contract, claiming that he had failed to repay a loan that he had taken out from the bank. The Supreme Court ruled in favor of the bank, finding that Lanier had indeed breached his contract with the bank. The court held that Lanier was liable for the full amount of the loan, plus interest, and that the bank was entitled to recover its costs and attorney's fees. The court also held that the bank was entitled to an injunction preventing Lanier from disposing of any of his assets until the debt was paid. The decision in Bank v. Lanier established the principle that a party who breaches a contract is liable for the full amount of the debt, plus interest and costs. It also established the principle that a court may issue an injunction to prevent a party from disposing of assets until the debt is paid. This case is still cited today as an example of the court's willingness to enforce contracts and protect creditors.

In Bank v. Lanier, the Supreme Court was asked to decide whether a bank could sue for damages against an individual who had fraudulently obtained money from it. The majority opinion held that the bank did not have standing to bring such a suit because it was not specifically mentioned in the statute allowing for such suits and thus lacked statutory authority to do so. However, Justice Field dissented on this point and argued that while there may be no explicit mention of banks in the statute, they should still be allowed to bring suit as long as their rights were violated by fraudulent means. He reasoned that since banks are engaged in business activities similar to those of individuals or corporations, they should receive equal protection under law when wronged by another party's fraudulent actions. Furthermore, he argued that denying them accession would lead only serve injustice and encourage further frauds upon banking institutions without any legal recourse available for redressal of grievances suffered at the hands of wrongdoers.