Rules for Radicals and Reveille for Radicals by Saul D. Alinsky
This is the 48 Laws of Power written in more of an idealist, activist tone. Alinsky was the liaison for many civil rights, union and student causes in the late 50’s and 60’s. He teaches how to implement your radical agenda without using radical tactics, how to disarm with words and media as opposed to arms and Utopian rhetoric.
Boyd: The Fighter Pilot who Changed the Art of War by Robert Coram
Boyd was probably the greatest post-WWII military strategist; he developed the F-15 and F-16, revolutionized ground tactics in war and covertly designed the US battle plans for the Gulf War. He shunned wealth, fame, and power all to accomplish what he felt needed to be accomplished. Coram captures his essence in a way that no other author has touched.
Of course you also need to read 33 Strategies of War by Robert Greene (Amazon), The Book of Five Rings by Musashi (Amazon), The Strategy Paradox by Raynor (Amazon), Machiavelli’s The Prince (Amazon), and Von Clausewitz’ On War (Amazon). In terms of classics, The History of the Peloponnesian War (Amazon) is an obligation for every student of history.
For a whole list of books on the US Civil War, start here. For a more complete list of recommendations see my list of 43 Books About Warand 24 Books To Hone Your Strategic Mind.