[Two people sitting in rubble of the auditorium in the Medical School, University City, Madrid]

[Republican soldier playing guitar, another reading the paper, University City, Madrid]

[Republican soldiers aiming machine guns through peepholes, University City, Madrid]

[Men of the International Brigades in a laboratory of the Medical School building of the University City, Madrid]

[A family portrait and other belongings on the street after an air raid, Madrid]

[Men and child on a truck, Madrird]

[Ernest Hemingway and Herbert Matthews at breakfast table, Valencia, Spain]

[Woman inventorying painting with two Republican soldiers, convent of Las Descalzas Reales, Madrid]

[Members of the International Brigades with gun, looking out a window, in or around University City, Madrid]

[Two Republican soldiers aiming rifles through barricaded window, University City, Madrid]

[Enemy flag captured in Battle of Brunete presented at International Congress of Antifascist Writers, Madrid]

[Men of the International Brigades catapulting grenades in the vicinity of the slaughterhouses near the University City, Madrid]

[Older woman and child on the platform of a subway station in the aftermath of Nationalist air raids, Madrid]

[Two boys on a roof top pointing at smoke rising in the distance of the city, Madrid, Spain]

[Republican soldier sitting next to an empty bath tub, near University City, Madrid]

[Women and children near a poster encouraging "sangre fria" (cold blood) courage, Madrid]

[Woman and man standing on the sidewalk next to rolled bedding after an air raid, Madrid]

[André Malraux (left) and Ilya Ehrenburg (center) at the Second International Congress of Writers for the Defense of Culture, Valencia]

[Group of women and children living on the platforms of subway stations in the aftermath of Nationalist air raids, Madrid]

[Member of the International Brigades helping a wounded comrade in the vicinity of the slaughterhouses near the University City, Madrid]

[Group of women and children living on the platforms of subway stations in the aftermath of Nationalist air raids, Madrid]

"No pasaran!" ("They will not get through!") Inhabitants of Madrid building barricades against approaching Nationalist troops

[Two Republican soldiers aiming gun out a window of the Medical School building, University City, Madrid]