Share This Article 1. On 15 May 1918 regular airmail service in the US was initiated by this government department. The US Army The Federal Aviation Administration The US Postal Service The US Navy 2. For years it was a dictum at the US Army War College that no matter what the question, the answer was always this man. Grant Clausewitz Napoleon Mahan 3. This battle is called the “Gettysburg of the Indian territory” The First Battle of Cabin Creek The Battle of Honey Springs The Battle of Perryville The Second Battle of Cabin Creek Loading …