Martens and his staff accepted a number of invitations to speak at radical meetings in New York City and elsewhere, activity which drew the ire of conservative forces in America.Stevenson (ed.), Revolutionary Radicalism, vol. 1, pg. 644. Martens retained close contact and warm relations with the Socialist Party of America (SPA) and the Communist Labor Party of America (CLP) which emerged from the SPA's organized left wing late in 1919.
