Social activist and war correspondent Martha Gellhorn with her new husband Ernest Hemingway on their 1940 honeymoon.

When right-wing military leaders revolted against the elected socialist government of Spain in 1936, many of the American correspondents who rushed to cover the Spanish Civil War didn't try very hard to conceal who they were rooting against, even though the United States was neutral in the conflict. After all, the right-wing Nationalist army led by Gen. Francisco Franco had some ugly backers — the fascist regimes of Adolf Hitler and Benito Mussolini. (The left-wing Republican regime eventually became entangled with an equally unsavory patron, Soviet dictator Josef Stalin, but the brutality of his regime wasn't yet widely known.)

One of the most prominent — and partisan — was Martha Gellhorn, a Bryn Mawr dropout and friend of first lady Eleanor Roosevelt who was sent by Collier's magazine to cover the war. Gellhorn, who was married for a time to Ernest Hemingway, saw journalism as a way to fight for a better world and chided other correspondents for "writing less than they know and caring less than they should." To her, objectivity was a sham. "You go into a hospital and it's full of wounded kids. So you write about what you see," she once said. "You don't say there's 37 wounded children in this hospital, but maybe there's 38 on the other side. You write about what you see."

Novelist George Orwell also showed up in Spain to cover the war as a journalist. But his sympathy for underdogs and nagging sense of moral duty got the better of him, and he soon enlisted in a socialist militia. Orwell's 1938 memoir on the experience, the complete text of which is still available on the Internet, contains moving vignettes of naíve young soldiers thrust into the cruel vortex of war.

One section describes his own introduction to combat: " ... presently the sentry on my left, leaving his post in the typical Spanish fashion, sidled up to me and began urging me to fire. I tried to explain that at that range and with these rifles you could not hit a man except by accident. But he was only a child, and he kept motioning with his rifle towards one of the dots, grinning as eagerly as a dog that expects a pebble to be thrown. Finally I put my sights up to seven hundred and let fly. The dot disappeared. I hope it went near enough to make him jump. It was the first time in my life that I had fired a gun at a human being."