Hard facts about the [1886 Haymarket] bombing [in Chicago] still remain clouded and the guilt of most, if not all, of the eight convicted men is still questioned. The innocence of the four executed anarchists has been largely proven retroactively. It is one of the “Haymarket Martyrs,” Albert R. Parsons, executed on November 11, 1887, who connects Paul Grottkau the political activist to Paul Grottkau the professional photographer, via this singular image of a mixed-race woman. […]