Earl Alonzo Brininstool was born in Warsaw, New York on Octobr 11, 1870. His education included grade school and a degree from a small business college. In 1895, he and his wife moved to Los Angeles, California where he pursued a career in journalism. After working for local newspapers for a while, he struck out on his own to become a freelance writer. He wrote an extnesive collection of poetry, mostly involving western themes, and contributed articles to magazines such as Hunter-Trader, Sunset, Frontier Times, Outdoor Life and Winners of the West.

His most noted work, consisting of a compilation of several of his articles, Troopers with Custer,was published in 1952, and was actually an update of his 1925 work A Trooper With Custer. Other books included biographies of Crazy Horse, Red cloud, and dull Knife. there were also biased treatments of Reno and Benteen.

Over the years, Brininstool developed an extensive correspondence with other notable of the Custer Battle, namely Walter Camp, Fred Dustin, William J. Ghent, Charles Kuhlman, and Col Graham. he was sponsored by Gen. Edward Godfrey for companion membership in the order of Indian Wars, an organization dedicated to veterans of the frontier campaigns. Brininstool sought out and carefully compiled the stories of many survivors of the Reno command- Lt Varnum, Sgt O'Neill, Pvt Slaper, and trumpeter Martini. He also avidly tracked down the stories of so-called "survivors" of the Custer phase of the battle. Of the greater than 70 stories that he collected, none were found to have any hint of veracity.

Influenced significantly by the Benteen-Goldin letters, Brininstool became less enamored of Custer and his strategy during the battle, and became a defender of Reno and Benteen. He stated that although Custer was undoubtedly courageous, his arrogance and ego seriously hampered his entire career and led ultimately to his downfall at the Little Bighorn.

Brininstool died at the age of 86 on July 28, 1957 in Los Angeles.