Marshall graduated first in his law school class in 1933 at Howard University and began practicing law in Baltimore. He eventually became chief legal counsel for the NAACP and argued a number of cases before the Supreme Court, including his most famous, Brown v. Board of Education of Topeka, Kansas in 1952, the case which struck down the "separate but equal" doctrine that permitted school segregation. In total, Marshall won 29 out of the 32 cases he argued before the Supreme Court.
President John F. Kennedy appointed Marshall to the US Court of Appeals for the Second Circuit in 1961 and President Johnson appointed him as Solicitor-General in 1965. Johnson said that appointing Marshall to the Supreme Court was "the right thing to do, the right time to do it, the right man and the right place." Marshall was confirmed as an Associate Justice by a Senate vote of 69-11 on August 31, 1967.
The text of Johnson's remarks at the press conference introducing Marshall as his choice for the court can be found here.
Marshall served on the Court for the next twenty-four years, compiling a liberal record that included strong support for Constitutional protection of individual rights, especially the rights of accused persons in criminal cases. He retired from the court in 1991 and died on January 24, 1993 of heart failure at the age of 84.