What kind of troops did America send to Vietnam in the early 1960s?

The Green Berets

Explanation:

The United States role in the Vietnam war increased into full involvement from 1955 to 1973. In May, 1961, President John Kennedy sent 500 United States Army Special Forces personnel to South Vietnam. These special forces also known as the Green Berets are specially trained in information operations, counterterrorism, counterinsurgency, unconventional warfare, special reconnaissance, direct action, foreign internal defense and weapons of mass destruction.

The green berets were sent to South Vietnam to train south Vietnamese soldiers. By November 1963, president Kennedy had increased the number of military personnel to 16000, just before his assassination.