National Vietnam War Veterans Day is a US holiday observed annually on March 29. It recognizes veterans who served in the US military during the Vietnam War.
March 29 was chosen as National Vietnam War Veterans Day because on March 29, 1973, Military Assistance Command, Vietnam (MACV) was disbanded and the last U.S. combat troops departed the Republic of Vietnam. The last unit was elements of MACV's Infantry Security Force (Special Guard), actually special couriers.