The True Origin of the US Marine Corps' 'Oorah' Call
(U.S. Marine Corps/Cpl. Ali Azimi)
Military.com | By Blake Stilwell
Each branch of the military has its own distinctive lingo.
Nothing says "I'm in the Air Force" more than an airman calling their supervisor by their first name. "Hooah" is the Army's answer to literally everything, while the Navy has an entirely different second language. For the Marine Corps, one of the first words new enlisted Marines learn in boot camp is "oorah."
A Marine journalist went searching for the origin of the word back in 2004. He found a lot of scuttlebutt surrounding its origin, but no clear facts -- at least, not at first. Like many aspects of Marine Corps culture, it started out with a small group of Marines and slowly spread to the entire service. It's been Marine Corps custom ever since.
"Oorah" is a relatively new addition, especially considering how old the Marine Corps and many of its traditions are. The Corps' Eagle, Globe and Anchor symbol dates back to 1868. The slogan "A Few Good Men" actually dates back to 1779 when the service's members were called the Continental Marines. However, the Continental Marines didn't go around shouting "oorah!"
https://www.military.com/history/true-origin-of-us-marine-corps-oorah-call.html