The 27th, 30th, 40th and 48th Armored Divisions, were created from core units of the 27th "New York" Infantry Division, the 30th " Dixie" Infantry Division, the 40th "Sunrise" Infantry Division and the 48th Infantry Brigade. All of these are or were National Guard units. After World War Two, the Army imagined creating combined Infantry/Armored Divisions, the forerunners of today's Mechanized Infantry Divisions. These changes began shortly after the Korean war and some remined in service to their states until the late 60's.

In 1967, the Army began reorganizing these units. The 27th Armored Division became a Brigade of the 50th Armored Division of the New Jersey National Guard. The 40th and 30th began transitioning back to their traditional roles as Infantry Divisions.

Today the 27th and 40th Divisions are Mechanized Infantry Divisions combining Infantry and Armored Regiments for the New York and California National Guards. The 30th and 48th were converted to enhanced Separate Infantry Brigades of the Mississippi and Georgia National Guard and are scheduled to be intergrated into combined regular Army and National Guard Divisions.