THREE MAJOR CHANGES:There were three major changes to the enlisted rank structure during the Korean War that led closer to today's system. The Career Compensation Act of 1949 turned the pay grade system upside down, placing privates in the pay grade E-1 and master sergeants in pay grade E-7. In 1954, sergeant major and first sergeant are brought back by the Marine Corps in the pay grade E-7 and placed above master sergeant. The Career Compensation Act was amended, authorizing the pay grades E-8 and E-9. The two new pay grades did not alleviate overcrowding at the top.PUSAN PERIMETER:On 25 June 1950, eight divisions of the North Korean People's Army crossed the 38th parallel and invaded the Republic of Korea. Gen. Douglas MacArthur requested a Marine regimental combat team to be deployed to the Far East. Within just five days, the 1st Provisional Marine Brigade, elements of the 5th Marines with Marine Air Group 33, were in route to Pusan, Korea. The "Fire Brigade" stopped the North Korean attacks in its area before being pulled to reinforce the 1st Marine Division landing at Inchon. The Marines' complex amphibious landing at Inchon and recapture of the South Korean capital of Seoul broke the back of the North Korean People's Army invasion.FIRE BRIGADE:The Marines were used as fire brigades, moving from place to place to stamp out enemy threats. Not only did the Marines effectively beat back the North Korean attacks, but they spearheaded the first U.N. offensive of the war. The fire brigade had restored the confidence of the U.N. troops by destroying of the myth that the North Koreans were invincible.CHOSEN FEW:From Seoul, the Marines moved north. The weather was turning bitter cold as the Marines reached the far end ofthe Chosin Reservoir when they were unexpectedly attacked and cut off by twelve Chinese Communist Divisions. This marked the first time American troops did battle against communist forces. Through sheer courage and perseverance, the integrated ground and air actions enabled 14,000 Marines, soldiers, and Royal Marine troops to fight their way 78 miles in temperatures reaching negative 40 degrees Fahrenheit to break out of the entrapment. Never in history has small unit leadership proven so successful in an organization than it did among the heroes of the Chosin Reservoir.