In 1909 Holmes helped establish the National Association for the Advancement of Coloured People (NAACP). Early members included Mary White Ovington, Josephine Ruffin, Mary Talbert, Mary Church Terrell, Inez Milholland, Jane Addams, Florence Kelley, Sophonisba Breckinridge, John Haynes Holmes, Mary McLeod Bethune, George Henry White, William Du Bois, Charles Edward Russell, John Dewey, William Dean Howells, Lillian Wald, Charles Darrow, Lincoln Steffens, Ray Stannard Baker, Fanny Garrison Villard, Oswald Garrison Villard and Ida Wells-Barnett. A socialist and pacifist, Holmes was appalled by the way people were being persecuted for their political and religious beliefs during the First World War.
In 1920 he joined with others to establish the American Civil Rights Union (ACLU). Early members included Roger Baldwin, Norman Thomas, Jane Addams, Freda Kirchwey, Chrystal Eastman, Florence Kelley, Lillian Wald, Felix Frankfurter, Oswald Garrison Villard, Paul Kellogg, Clarence Darrow, John Dewey, Charles Beard, Abraham Muste, Elizabeth Gurley Flynn and Upton Sinclair.
The ACTU's main concern was to defend the civil rights that were guaranteed in state and federal constitutions. This included:
(1) First Amendment rights: These include freedom of speech, association and assembly, freedom of the press, and freedom of religion, including the strict separation between church and state.
(2) Equal protection of the law: The right to equal treatment regardless of race, sex, religion, national origin, sexual orientation, age, physical handicap, or other such classification. These rights apply to the voting booth, the classroom, the workplace and the courts.
(3) Due process of law: The right to be treated fairly when facing criminal charges or other serious accusations that can result in such penalties as loss of employment, exclusion from school, denial of housing, or cut-off of benefits.
(4) The right of privacy and autonomy which cannot be penetrated by the government or by other institutions, like employers, with substantial influence over the individual's rights. Holmes was also involved in several other political campaigns. He helped Margaret Sanger establish the Planned Parenthood Movement. He was also a member of the Fellowship of Reconciliation, The War Resisters League and the League for Industrial Democracy.
John Haynes Holmes died in 1964.