The Supreme Court case Reaves v. Ainsworth in 1910 revolved around the issue of military jurisdiction over civilian crimes committed on a military reservation. The plaintiff, Reaves, was convicted by a court-martial for larceny and assault with intent to kill within Fort Leavenworth Military Reservation but sought habeas corpus relief arguing that the military tribunal lacked jurisdiction as he was not enlisted in any branch of the armed forces at the time of his offenses. However, Major General Ainsworth contended that since Fort Leavenworth is under exclusive federal control and has been set aside for use as an army post, it falls within military jurisdiction regardless if one is a soldier or civilian. The Supreme Court ruled against Reaves stating that Congress had authority to provide for trial and punishment by courts-martial of such offenses committed within these boundaries even though they were perpetrated by civilians. This decision affirmed Congress's power to regulate areas under its direct control like federal enclaves including forts or arsenals purchased from states with their consent.

In the dissenting opinion for Reaves v. Ainsworth, it was argued that the majority's decision to deny Mr. Reaves' claim for additional pay as a retired military officer was incorrect and unjustified. The dissenting justices believed that under the Act of Congress from 1899, which provided increased retirement pay for officers who had served in both civil war and Indian wars, Mr. Reaves should have been entitled to this increase due to his service during these periods of conflict. They contended that there were no stipulations within this act stating an individual must serve in active combat or be physically present on a battlefield to qualify; instead, they asserted any form of service during these times should suffice as qualification criteria per the language used by Congress when drafting this legislation. Therefore, they disagreed with their colleagues' interpretation and application of law in denying Mr.Reave's rightful claim.