Byrd served in the Senate of Virginia from 1948 to November 1965, where he was Chairman of the General Laws Committee. As a major player in the Byrd Organization, he supported Massive Resistance, a movement against desegregation which his father announced and led, despite the 1954 U.S. Supreme Court decision in "Brown v. Board of Education". In 1956, Byrd provided strong and integral support of legislation that became known as the Stanley Plan (after then-Virginia Governor Thomas B. Stanley, a Byrd Organization member). The plan required the closing of all desegregating schools, even those desegregating pursuant to court order. It was invalidated within three years by both federal courts and the Virginia Supreme Court. The plan's legacy of racially based school closures and funding disruptions persisted in some localities until 1964, and was the nadir of the Byrd political brand.