<Li> 1954--Two months after the Geneva conference, North Vietnam forms Group 100 with headquarters at Ban Namèo . Its purpose is to direct, organize, train and supply the Pathet Lao to gain control of Laos, which along with Cambodia and Vietnam formed French Indochina . </Li> <Li> 1955--North Vietnam launches an' anti-landlord' campaign, during which counter-revolutionaries are imprisoned or killed . The numbers killed or imprisoned are disputed, with historian Stanley Karnow estimating about 6,000 while others (see the book "Fire in the Lake") estimate only 800 . Rudolph Rummel puts the figure as high as 200,000 . </Li> <Li> November 1, 1955--President Eisenhower deploys the Military Assistance Advisory Group to train the Army of the Republic of Vietnam . This marks the official beginning of American involvement in the war as recognized by the Vietnam Veterans Memorial . </Li> <Li> April 1956--The last French troops leave Vietnam . </Li>

When did the usa enter the vietnam war