He served as spiritual advisor to Dr. Martin Luther King, Jr., Sherwood Eddy, James Farmer, A. J. Muste, and Pauli Murray.
Dellinger had contacts and friendships with such diverse individuals as Eleanor Roosevelt, Ho Chi Minh, Martin Luther King, Jr., Abbie Hoffman, A.J. Muste, Greg Calvert, David McReynolds and numerous Black Panthers, including Fred Hampton, whom he greatly admired.
Cohn was a co-founder of Brookwood Labor College in 1924, an initiative associated with labor educator A. J. Muste.
From 1929 to 1933, Hardman served as a member of the executive committee of the Conference for Progressive Labor Action (CPLA), a radical labor organization associated with A. J. Muste and Brookwood Labor College.
The original Militant terminated in 1934 at the time of the merger of the Cannon-led CLA with the American Workers Party headed by A. J. Muste to form the Workers Party of the United States (WPUS).