Complex sentence: In 1957, to test new materiel at Fort Ord, California, the US Army's Combat Developments Command formed the 194th Armored Brigade, which assumed the mission of the tank battalion of the 5th Infantry Division previously there.
Split into simpler sentences: In 1957, the 194th Armored Brigade was formed by the US Army's Combat Developments Command to test new materiel at Fort Ord, California. It assumed the mission of the tank battalion of the 5th Infantry Division previously there.