10 May 1797 – The 1st American Navy ship built under the Naval Act of 1794 was launched. The USS United States was a wood hulled, three masted heavy frigate that was built along with five other similar frigates. She would protect American merchant ships until the Civil War when the Confederacy would capture and later scuttle her. She was raised by the Union but later broken up in 1865.
10 May 1972 – The A-10 Thunderbolt (Warthog) undergoes its first test flight. The first “Hawg” would be accepted into service on 30 March 1976. The A-10 was designed around the 30 mm GAU-8 Avenger rotary cannon and built as a dedicated Close Air Support Platform (CAS), this plane is a flying tank with a titanium cockpit and can take a serious beating, while giving one, before being forced to land. A common myth floating around is that if the A-10 fires its main gun for to long, it can stall mid air. While this is false, it is easy to believe when you see it shoot!
12-13 May 1865– Battle of Palmito Ranch. Considered by some to be the last battle of the Civil War, Union and Confederate forces would clash on the banks of the Rio Grande River east of Brownsville, Texas. The battle was prompted by the Union commander who had never been in combat. After small initial success on the 12th they would be defeated on the 13th by Confederate forces using artillery to their great advantage. Union Private John J. Williams is believed to be the last man killed in this battle and thus the last Solider to die in combat in the Civil War. That this battle was the last one fought in the Civil War is disputed, as the Confederacy has ceased to exist at this point and this can be considered a post-war action as a result.
14 May 1804– The Corps of Discovery, under Captains Lewis and Clark, departed Camp Dubois and made their way up the Missouri River to St. Charles, MS. They then embarked on their great expedition to explore the newly acquired American territory and reach the Pacific Ocean.