Since World War II, The 3rd United States Infantry Regiment (The Old Guard) has served as the official Army honour guard and escort to the President, and it also provides security for Washington, D.C., in time of national emergency or civil disturbance. Arlington National Cemetery's Tomb of the Unknowns is guarded by members of the U.S. 3rd Infantry Regiment. Since 2007, a Joint-Service Drill Competition has been held every April in front of the Reflecting Pool of the National Mall. Other ceremonial military units also include the Royal Guards of Hawaii of the Air National Guard and the High Frontier Honor Guard at Peterson Air Force Base. The organized militia for the Connecticut State Militia also maintains a ceremonial guard unit, the Governor's Foot Guard 
Many local, state, national and federal public safety agencies in the United States maintain Honour Guards, Pipes & Drums and Buglers, including fire departments, law enforcement agencies, emergency medical services, and search and rescue agencies, who typically use adaptations of military honour guards, and honour those who die in the line of duty (LODD-Line of Duty Death), off-duty but still on the job, and retirees, as well as participating in support of other agencies, and parades. Some Law Enforcement agencies are able to maintain a Rifle Team for 'three volley' salutes. Most, even those within major career paid agencies, are not paid for performing and preparing for the honour guard duty.
some of this information came from Wikipedia