March 15, 1965 – Gen. Harold K. Johnson, Army Chief of Staff, reports on his recent visit to Vietnam to President Lyndon B. Johnson and Secretary of Defense Robert McNamara. He admitted that the recent air raids ordered by President Johnson had not affected the course of the war and said he would like to assign an American division to hold coastal enclaves and defend the Central Highlands. General Johnson also advocated creating a four-division force of Southeast Asia Treaty Organization (SEATO) and U.S. troops to patrol the Demilitarized Zone along the border separating North and South Vietnam and Laos. Nothing ever came of General Johnson’s recommendation on the SEATO troops, but President Johnson ordered the 173rd Airborne Brigade to Vietnam in May 1965 and followed it with the 1st Cavalry Division (Airmobile) in September of the same year. These forces, along with the first contingent of U.S. Marines–which had arrived in March–were only the first of a massive American build up. By 1969, there were more than 540,000 U.S. troops in South Vietnam.