Their first action was the invasion of the Marshall Islands on 1 February 1944, securing the first portion of the Japanese Empire to be conquered by the United States in World War II.

Captain Joseph J. McCarthy, Commanding Officer, Co. G, 2nd Battalion, 24th Marines, and a Chief in the Chicago Fire Department, was awarded the Medal of Honor for his gallantry during the battle.

While maintaining its mission of providing security, 2nd Battalion, 24th Marines was also responsible for the handling and processing of over 10,300 enemy prisoners of war in a 96-hour period.

The battalion trained at Camp Pendleton until Sept. of that year when they relocated to Mahmudiyah, in the North Babil Province of Iraq, an area known as the "Triangle of Death".

Two-time Pulitzer Prize Winner John F. Burns, the Chief Foreign Correspondent of The New York Times described his time spent with 2/24 this way: "A week with the 2/24 Marines at their bases 15 to 30 miles south of Baghdad, in the heart of the area known as the Triangle of Death, was a window on the demands being made of reservists, and on the resourcefulness and resilience they bring to the challenges.

There is little they cannot do, with hard work and improvisation, the battalion's officers say, reflecting the widely varied backgrounds of the men in the Chicago-based unit - doctors, policemen,[3] engineers, teachers, carpenters, truck drivers, lawyers, computer specialists, community counselors, college students, to name a few.

"[4] After establishing additional strong points in the area, working closely with the Iraqi Army and Police, providing security for the first-ever open democratic elections in Iraq and arresting over 1,000 suspected insurgents (with an incredibly high conviction rate,) 2/24 returned to California in March 2005.

The Marines taught basic military tactics to groups of soldiers from the Forces Armees Nigeriennes and also provided humanitarian support to some of Niger's neediest citizens.

[5] In May 2006, Echo Company of 2/24 participated in Operation Noble Shirley in Israel by conducting desert warfare and joint counter-terrorism training with the Israeli Defense Forces [IDF].