King watched with growing dismay as U.S. military involvement in Vietnam escalated throughout 1965 and 1966. He abhorred the war on principle and worried that national resources needed to combat poverty and advance the cause of civil rights were being consumed by the Pentagon. Both as a Nobel Peace Prize recipient and as the world’s foremost advocate for nonviolence, King felt compelled to take a public stand against the war.
In an impassioned address delivered at New York City’s Riverside Church on April 4, 1967, he denounced U.S. action in Vietnam, declaring, "If America’s soul becomes totally poisoned, part of the autopsy must read Vietnam." On April 15, King walked arm in arm with Dr. Benjamin Spock (left) and Monsignor Charles Owen Rice of Pittsburgh (right) as they and thousands of protesters marched from Central Park to the United Nations Plaza, where King addressed a mammoth antiwar rally.