The 5th Marine Regiment is the most highly decorated regiment in the Marine Corps. They have been involved in every major conflict since June of 1917, during World War I.
"Today, the Regiment continues to participate in exercises and contingency deployments with the 1st Marine Division, and to prepare forces for deployment with the 31st MEU (SOC). Ever ready to answer the nation’s call, the “Fighting Fifth” is recognized as the Marine Corps’ most highly decorated regiment. "
-5th Marine Regiment History