A lot but due to today's environment I will note "The Origins of Totalitarianism" by Hannah Arendt. It provides a stark warning about the seductive nature of totalitarianism across the full political spectrum. I will provide the following warning, like any historical work one can easily find parallels to contemporary events based on one's own confirmation bias - it will be easy to find similarities to groups you do not like. But it is a book that should be read and contemplated.
The 5000 Year Leap - Principles of Freedom 101
W. Cleon Skousen
I feel this should be required reading and about time I read it again. The book talks about 28 principles which are outlined here (https://nccs.net/blogs/articles/principles-of-liberty-in-our-founding-documents) This book did inspire me to make changes in my life. One in particular was working to become debt free. Paid off everything but the house ($45K in debt paid in 12 months).
That Every Man Be Armed: The Evolution of a Constitutional Right
More of an academic paper going throughout history (Greece, Rome -> England -> Revolution -> Today). The author, Stephen Halbrook, has won and wrote briefs for several Supreme Court cases. It at times feels like you are drudging through it, again academic paper, but it is one the most complete historical references on the 2A I know of.
On my reading list:
Patriot's History of the United States
From Columbus's Great Discovery to the War on Terror
Larry Schweikart and Michael Allen
Daunting at over 800 pages but easily broken up into chunks.