Ingles was born in San Antonio, Texas, and raised in the small town of Jourdanton, Texas. He served in the United States Navy during World War II and later attended the University of Texas at Austin, where he earned a bachelor's degree in journalism.
After working for several years as a journalist, Ingles began writing books on Texas history. His first book, "The Story of San Antonio," was published in 1955. He has since written more than 30 books, including "The Handbook of Texas," "The Texas Rangers: A History," and "The Battle of the Alamo."
Ingles's work has been praised for its accuracy, insight, and readability. He has been awarded numerous prizes, including the Texas State Historical Association's Carr P. Collins Award, the Texas Institute of Letters' Lon Tinkle Award, and the Western Writers of America's Spur Award.
In addition to his work as an author, Ingles has also been active in historical preservation. He served as the president of the Texas State Historical Association from 1983 to 1985, and he is a member of the boards of directors of the Alamo Mission Foundation and the National Trust for Historic Preservation.