Despite the fact that Stephen Crane was not a war veteran, The Red Badge of Courage has long been praised for its realism.
It is known that Crane read Civil War battle accounts published by Century magazine that began in 1877 and ran for three years. Century's publishers ran painstakingly detailed accounts of battles from both Union and Confederate perspectives including Sherman, Grant, Sheridan, McClellan, Longstreet, and Beauregard. The series was quite popular, and the recollections were later collected into a set of four books.
It is also thought likely that Stephen Crane interviewed Civil War veterans and recorded their impressions. When Crane was a boy, he lived in Port Jervis, NY, and he returned there as an adult. It is thought that he spoke with veterans who had served with the 124th New York Volunteer Infantry Regiment and fought at Chancellorsville, Fredericksburg, Gettysburg, and Appomattox. While Crane lived with his brother in Port Jervis, there were veterans living on the same street, and his brother's law office shared a building with a veteran's post.
Crane was dissatisfied with the emotionless reporting of the battles in the stories published by Century. He was curious about the inner life of soldiers and felt it was important to explore how men felt in battle.
Crane began writing The Red Badge of Courage in 1893 while living with his brother and his wife (nee Fleming) in New Jersey. The novel was finished in New York the following year.