Dalton Trumbo was born James Dalton Trumbo on December 5, 1905 in Montrose, Colorado. His father was hardworking yet financially unsuccessful, but the family lived happily. When Trumbo was still young, his family moved to Grand Junction, Colorado, a larger town. Trumbo was obviously too young to fight in World War I, but he remembers his father and the rest of their community voting for Woodrow Wilson to keep America out of the war.

After Trumbo began college at the University of Colorado, his father decided to move the family to Los Angeles in the hope of making more money. Their financial situation remained shaky, however, so Trumbo dropped out of college and joined them in 1925. In Los Angeles, Trumbo worked at a bakery. In Johnny Got His Gun, many of Joe Bonham's early memories are Trumbo's from Colorado and then Los Angeles.

After his father's death, Trumbo picked up a second job and enrolled at the University of Southern California. He had begun writing short stories back in Colorado and had continued to do so in California. He began to publish articles and short stories for magazines such as Vanity Fair and The Hollywood Spectator. Trumbo was offered the associate editor position at The Hollywood Spectator, and he finally took it and abandoned his bakery job.

In 1934, Warner Brothers hired Trumbo as a reader in their story department, thus beginning his long career in the film industry. Trumbo continued to publish short stories and then published his first novel, Eclipse in 1935. He was promoted to junior writer at Warner Brothers, but then was fired when he refused to resign his membership to the left-wing Screen Writers Guild. Rehired by Columbia Pictures, Trumbo went on to be one of the highest-paid writers in Hollywood in the 1940s.

Trumbo conceived of the project of Johnny Got His Gun early in the 1930s, after reading an article about the Prince of Wales's visit to a Canadian veterans hospital to see a soldier who had lost all of his senses and his limbs. Trumbo did not begin work on the novel until 1937. It was finally published in 1939, two days after the outbreak of World War II. Though the novel was a pacifist piece published in wartime, it was well reviewed and won an American Booksellers Award in 1940. When the first print run finished, however, Trumbo agreed that the novel should not be reprinted until the end of World War II.

After the war, Trumbo and several other Hollywood writers, directors, and producers were called to testify before Senator Joseph McCarthy's House Committee on Un-American Activities. Ten of these men—who came to be known as the Hollywood Ten—refused to answer questions about their own involvement in the Communist Party or to give names of others. On the stand, Trumbo famously said to chief investigator Richard Stripling, "Very many questions can be answered 'Yes' or 'No' only by a moron or a slave." All ten men were sentenced to prison terms and blacklisted from the film industry.

Trumbo served his one-year prison sentence and continued to write scripts for the black market. He was able to legitimately write scripts again in 1959. Trumbo continued to write successful screenplays, including a film adaptation of Johnny Got His Gun, until his death in 1976.

Johnny Got His Gun enjoyed increased popularity around the Vietnam War. Today the novel continues to be read as a prescient anti-war novel, but also as part of a larger movement of proletarian writing during the years of the Depression.