2 May 1946: Marines from Treasure Island Marine Barracks, under the command of Warrant Officer Charles L. Buckner, aided in suppressing the three-day prison riot at Alcatraz Penitentiary in San Francisco Bay. WO Buckner, a veteran of the Bougainville and Guam campaigns, ably led his force of Marines without suffering a single casualty.
 
5 May 1983: In Beirut, Lebanon, a UH-1N helicopter carrying the commander of the American peace-keeping force, Colonel James Mead, was hit by machine gun fire. The six Marines aboard escaped injury. Colonel Mead and his crew had taken off in the helicopter to investigate artillery and rocket duels between rival Syrian-backed Druze Moslem militiamen and Christian Phalangists that endangered French members of the multinational force.
 
8 May 1995: In the wake of the most devastating storm to hit the New Orleans area in more than 200 years, a group of Marines and sailors from Marine Forces Reserve demonstrated the quick response synonymous with the Navy/Marine Corps team. Within 24 hours of being called, Marines assisted in the evacuation of 2,500 civilians, and Navy corpsmen treated scores of flood victims.
 
10 May 1945: The 22d Marines, 6th Marine Division, executed a pre-dawn attack south across the Asa River Estuary and seized a bridgehead from which to continue the attack toward Naha, the capital of Okinawa.
 
15 May 1862: Corporal John Mackie, the first Marine to earn the Medal of Honor, was commended for service in the USS Galena during action against Confederate shore batteries at Drewry's Bluff which blocked the James River approaches to Richmond.
 
16 May 1945: The 22d and 29th Marines continued the attack against Half Moon Hill, a day characterized by the 6th Marine Division as the "bitterest" of the Okinawa campaign. By the 18th, the famed "Shuri line" had been broached.
 
22 May 1912: First Lieutenant Alfred A. Cunningham, the first Marine officer to be assigned to "duty in connection with aviation" by Major General Commandant William P. Biddle, reported for aviation training at the Naval Aviation Camp at Annapolis, Maryland, and Marine aviation had its official beginning.
 
23 May 1988: The V-22 Osprey, the world's first production tilt-rotor aircraft, made its debut during rollout ceremonies at Bell Helicopter Textron's Arlington, Texas, facility. More than 1,000 representatives from the military, industry, and media, gathered to hear various speakers, including Gen Alfred Gray, Commandant of the Marine Corps, praise the versatile rotor craft designed to meet the needs of 21st Century battlefields.
 
26 May 1969: Operation Pipestone Canyon began when the 1st Battalion, 26th Marines and 3d Battalion, 5th Marines began sweeps in the Dodge City/Go Noi areas southwest of Da Nang. It terminated at the end of June with 610 enemy killed in action at a cost of 34 Marines killed.
 
29 May 1991: Elements of a joint task force that included the 5th Marine Expeditionary Brigade departed the Bay of Bengal off the coast of Bangladesh after nearly two weeks of disaster relief operations following a devastating cyclone. The joint task force delivered tons of relief supplies using helicopters, C-130s, and landing craft in Operation Sea Angel.