Mornings on Horseback is a 1981 biography of the 26th President of the United States Theodore Roosevelt written by popular historian David McCullough, covering the early part of Roosevelt's life.

[2] "The process by which a spindly, ailing boy grew into this man is one of the enduring American mysteries."

– David McCullough[4] During his research for The Path Between the Seas, describing the history of the Panama Canal and Theodore Roosevelt's role in its construction, McCullough says "I was interested in knowing what was involved in the metamorphosis of this most conspicuous animate wonder.

"[4] The wealth of correspondence allowed him to reveal the life of a well-to-do Victorian American family in depth heretofore unseen.

"[5] McCullough speaks of the value in knowing who raised the future President: "If there was one discovery or revelation that meant the most, it was coming to know Theodore Roosevelt, Sr., who is central to this book, as he was in the life of his small namesake.