...president committed the first combat advisors to South Vietnam. That would be Eisenhower in 1954, following the defeat of the French at Dien Bien Phu. The first American death in Vietnam took place in 1956. The last time I looked, Eisenhower was president from 1952 to 1960, and Nixon was his VP.
Here is a year-by-year breakdown of American deaths in Vietnam from the "
Combat Area Casualties Current File (CACCF) in the Records of the Office of the Secretary of Defense (Record Group 330).":
<http://www.archives.gov/research_room/research_topics/vietnam_war_casualty_lists/statistics.html#year>
Kennedy authorized the issuance of NSAM 263 on October 11, 1963, authorizing the withdrawal of the first 1,000 troops from Vietnam.
<http://www.jfklancer.com/NSAM263.html>
On November 26, 1963, just four days after Kennedy's assassination, LBJ authorized the release of NSAM 273. NSAM 273 was the document that clearly showed LBJ's willingness, backed by the military-industrial complex as well as Big Oil, to escalate the war in Vietnam:
<http://www.jfklancer.com/NSAM273.html>
President Nixon actually presided over the end of American military involvement in the Vietnam War in 1973, five long years after LBJ decided not to run again for president. President Ford, our very first unelected VP and President, was the president who was in office when South Vietnam was finally overrun by the North Vietnamese. Ford attempted to secure additional funding for the rapidly deteriorating South Vietnamese government but could not get it through Congress.
I tend to view folks who believe that Kennedy was the first president to commit military advisors/troops to Vietnam as being one of the following:
1)Those who are lacking in basic knowledge about the history of American involvement in the Vietnam conflict;
2)Those who don't care about history;
3)Those who deliberately attempt to mislead others by manipulating actual historical facts.
By the way, I earned BAs in History and Political Science at Virginia Tech about thirty years ago, have personally served on active duty in the military, and consider myself to be an amateur military historian.