Badeau v. United States was a Supreme Court case decided in 1868. The case involved a dispute between the United States and a former Union Army officer, Major General Badeau, over the payment of back pay and allowances. Badeau had served in the Union Army during the Civil War and had been promised certain back pay and allowances for his service. However, the United States had failed to pay him the full amount due. Badeau sued the United States for the unpaid amount, and the case eventually reached the Supreme Court. The Supreme Court held that the United States was liable for the unpaid amount due to Badeau. The Court reasoned that the United States had a duty to pay Badeau the full amount due to him for his service, and that the United States had failed to fulfill this duty. The Court also held that the United States was not entitled to any setoff or counterclaims against Badeau, as the United States had failed to prove that Badeau was liable for any such claims. The decision in Badeau v. United States established that the United States was liable for the full amount of back pay and allowances due to a former Union Army officer for his service during the Civil War. The decision also established that the United States was not entitled to any setoff or counterclaims against the former officer.

In the case of Badeau v. United States, Justice Harlan delivered a dissenting opinion in which he argued that Congress had not intended to grant the government immunity from suit when it passed the Tucker Act in 1887. He noted that while there was language in the act granting such immunity, this language was added after an amendment and thus could not be seen as part of Congress’ original intent. Furthermore, he argued that if Congress had wanted to grant such broad immunity they would have done so explicitly rather than through an ambiguous amendment. In conclusion, Justice Harlan believed that since no clear statement existed granting government immunity from suit under the Tucker Act then it should be assumed none exists and therefore citizens should still have their right to sue for damages against federal agencies preserved by law.