The Artists International Association (A.I.A.) was founded in London in 1933 with a single purpose: to unify artists against fascism and war. Over the decade that followed, its members—among them, Peggy Angus, Pearl Binder, James Boswell, Percy Horton, Betty Rea, and Cliff Rowe—produced posters, prints, paintings, and murals in support of the Republican cause in Spain and against the rise of Hitler. The A.I.A. hasn’t been the subject of a major exhibition in over 40 years. Now, Towner Eastbourne is staging the most comprehensive show on the organization ever mounted, based on extensive new archival research by the curator Andy Friend. —Elena Clavarino