Complex sentence: The Army Organization Act of 1950 renamed the Medical Department the "Army Medical Service" (AMS) and on June 4,1968 the AMS was renamed the Army Medical Department (AMEDD).
Split into simpler sentences: The Army Organization Act of 1950 renamed the Medical Department the "Army Medical Service" (AMS). On 4 June 1968 the AMS was renamed the Army Medical Department (AMEDD).