On 1 September 1950, the 45th Infantry Division was activated as the first National Guard division to be deployed to the Far East theater since World War II. Nevertheless, it was not deployed to Korea until December 1951, when its advanced training was complete. Following its arrival, the division moved to the front line to replace the 1st Cavalry Division, who were then delegated to the Far East reserve, having suffered over 16,000 casualties in less than 18 months of fighting.