Overall, “Mr. Jefferson’s Hammer” leaves me with mixed emotions. I strongly wish it had covered more ground in its study of Harrison’s life, but I thoroughly enjoyed the portion of his public service that it did review. Owens’s writing style perfectly suited my desire to understand what happened in young Harrison’s life, and why. As a presidential biography, this book is imperfect insofar as it is incomplete – but it provides an excellent foundation for understanding this little-known former president and the frontier society in which he lived for much of his life.