USLANTCOM or USACOM was a Unified Combatant Command of the DoD. This command was active from 1947-1999. In 1999 the command was renamed United States Joint Forces Command and given new mission. 

USPACOM is the largest and oldest of the unified combatant commands. This command was renamed the U.S. Indo-Pacific Command on May 30th, 2018. The Headquarters of this command is located at Camp H. M. Smith in Oahu, Hawaii.

USNORTHCOM is tasked with providing protection to territories and national interests within the contiguous United states, Alaska, Canada and Mexico. This includes provision of military support to civil authorities within the U.S. if needed...