Donald Motier is the author of over 20 books including poetry, historical fiction, novellas, biographies and travel. Lincoln's Physician, a Biography of Dr. William Smith Wallace was inspired by Dr. Wayne C. Temple, retired Deputy Archivist of the Illinois State Archives and leading living authority on the life and family of Abraham Lincoln and is the author of many scholarly works.

Donald Motier has written three previous books on Lincoln and his family: Mystic Chords of Memory: Th e Lost Journal of William Wallace Lincoln (2009), Saving Lincoln: Mystic Chords of Memory Part 2 (2014) and He Had Rare Lights: A Biography of William Wallace Lincoln (2019). He lives and writes in Pennsylvania.