He was born in Lake Forest, Illinois and lived in Louisiana Jolla, California where he worked as an investment counselor He was the son of Ezra J. Warner, Junior. and grandson of Ezra J Warner, who were wholesale grocery business executives in Chicago, Illinois.
His father, Ezra J. Warner, Junior., was president & treasurer of wholesale grocery business Sprague, Warner & Company and vice president of the Chicago Orchestral Association. His mother was the former Marion Hall. He is buried in Lake Forest Cemetery in Lake Forest.
Ezra J. Warner III is well known for his work in Civil War biography.
Warner, Ezra J. Biographical Register of the Confederate Congress. Baton Rouge, Louisiana: Louisiana State University Press, 1975.
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Warner, Ezra J. Generals in Blue: Lives of the Union Commanders. Baton Rouge, Louisiana: Louisiana State University Press, 1964.
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Warner, Ezra J. Generals in Gray: Lives of the Confederate Commanders.
Baton Rouge, Louisiana: Louisiana State University Press, 1959.
