The key figure assassinated in Dallas in 1963 was President John F. Kennedy. On November 22, 1963, while riding in a motorcade through Dealey Plaza, Kennedy was shot by Lee Harvey Oswald, a former Marine. This tragic event shocked the nation and the world, leading to widespread mourning and conspiracy theories regarding the circumstances of his death. Kennedy's presidency was marked by significant events such as the Cuban Missile Crisis and the promotion of civil rights. His assassination had lasting impacts on American society and politics, leading to an era of tumult and distrust in the government.