Complex sentence: It was reactivated on 1 December 1954 as the 23rd Infantry Division, retaining the name "Americal" as part of its official designation, and served in the Panama Canal Zone until 10 April 1956, when it was again deactivated.
Split into simpler sentences: It was reactivated on 1 December 1954 as the 23rd Infantry Division, retaining the name "Americal" as part of its official designation. The division served in the Panama Canal Zone until 10 April 1956, when it was again deactivated.