A. Philip Randolph
Randolph finally realized his vision for a March on Washington for Jobs and Freedom on August 28, 1963, which attracted between 200,000–300,000 to the nation's capital. The rally is often remembered as the high-point of the Civil Rights Movement, and it did help keep the issue in the public consciousness. However, when President Kennedy was assassinated three months later, Civil Rights legislation was stalled in the Senate. It was not until the following year, under President Lyndon B. Johnson, that the Civil Rights Act was finally passed. In 1965, the Voting Rights Act was passed. Although King and Bevel rightly deserve great credit for these legislative victories, the importance of Randolph's contributions to the Civil Rights Movement is large.
Archibald Cox
The civil rights legislation that Kennedy was unable to see pass during his lifetime received the needed momentum from his death and the legislative skill of President Johnson. In 1964 the public accommodations bill passed as the Civil Rights Act of 1964. The obvious constitutional attack on the legislation was its constitutionality under the Fourteenth Amendment because it sought to regulate conduct that was not "state action." Cox and Assistant Attorney General and Head of the Civil Rights Division Burke Marshall, however founded the legislation on Congress's power to regulate interstate commerce. Although both John and Robert Kennedy questioned the optics of using the Commerce Clause, they did not object. Cox had no difficulty having the Court uphold the statute on that basis when he argued the cases in October.