Anti-war marches and other protests, such as the ones organized by Students for a Democratic Society (SDS), attracted a widening base of support over the next three years, peaking in early 1968 after the successful Tet Offensive by North Vietnamese troops proved that war's end was nowhere in sight.
The protests began in 1963 and spread at high speed throughout the United States. That was when the US polarized between those who advocated continuing the war and those who wanted immediate peace. The movement saw the participation of students, mothers of soldiers, African Americans, hippies, educators, religious, academics, journalists, lawyers, doctors, military veterans and in general all the factions of the American society of the time. The oppositions were from large peaceful demonstrations - highlighting on April 24, 1971, when more than 500,000 people marched peacefully through Washington D.C against the war - and violent street riots.
Veto power. Once Congress has passed a bill, the president has the power to veto that bill. In turn, Congress can override a regular presidential veto by a two-thirds vote of both houses.
