During the 1920s Kerr ceded control of the firm to the Proletarian Party of America, which continued the imprint as its official publishing house throughout its four decades of organized existence.

Control moved again during the decade of the 1960s, this time to a circle of Chicago radicals with close affinity to the ideas of the Industrial Workers of the World, who gave the company its current operating moniker.

[1] The wing of the Unitarian movement represented by the new semi-monthly magazine argued that personal character rather than literal belief in a body of written dogma marked the true "test and essence of religion.

"[1] These so-called "Unity Men" sought wider acceptance among Unitarians for this fundamental idea of the primacy of ethics over belief — a matter of no little controversy among the more conservative church mainstream of the day.

[2] A monthly magazine called Unitarian was established in January 1886 in an attempt to combat the ideas of the "Unity men" — who were seen as undermining Christianity in favor of what was characterized as a new "Ethical Culture.

"[3] As the controversy between the dissident "ethical" Unitarians and the more conservative "doctrinal" church mainstream heated up, the former felt the need for centralized and expeditious publication of books and other materials reflecting their views.

[6] In addition to books and magazines, the early Charles H. Kerr & Co. produced an array of pamphlets and hymnals for use of a network of "Unity Clubs" established around the country.

[5] Adams ran into financial difficulties shortly after taking over the magazine, however, and the publication was soon terminated and its subscription list sold to The Arena, a monthly edited by B. O.

[5] Kerr & Co. were greatly influenced by the growth of the People's Party during the 1890s and issued a wide array of titles on such prominent populist themes as monetary reform, railroad regulation, government control of the banking industry, and related matters.

Kerr & Co. followed this effort with the publication of volumes 2 and 3 of Capital, making use of original translations made by ISR editorial staff member Ernest Untermann and thus becoming the first publisher of this material in the world in the English language.

[13] Immediately after the war, Charles Kerr came into close contact with the Scottish-born Detroit radical John Keracher through the latter's "Proletarian University" movement and its need for Marxist literature.

Thereafter, the Proletarian Party controlled the operations of Kerr & Co., publishing a number of Keracher's works, including How the Gods Were Made (1929), Producers and Parasites (1935), The Head-Fixing Industry (1935), Crime: Its Causes and Consequences (1937), and Frederick Engels (1946).