In 1946, Ralph Helstein was the general counsel for the United Packinghouse Workers Union (UPWA), which had become a predominantly black worker organization. At the time there was a divisive left-right split in the union. As the only individual both sides trusted, Helstein was elected president of the union, thus beginning an era of positive change for the UPWA and its workers.Beyond Helstein's efforts for the UPWA, Marching with Dr. King: Ralph Helstein and the United Packinghouse Workers of America also examines the involvement of Helstein in the civil rights movement, his personal association with Martin Luther King, Jr., and how his actions as union president championed the rights of African Americans, women, and even an immigrant group outside the United States—the sugar workers in Puerto Rico. This text presents a unique perspective on the life of a labor leader, revealing the connection between Helstein's religious and philosophical ideas with his leadership of the UPWA union.