Hannah Arendt, On Revolution (New York: Penguin Books, 1963). Arendt analyzes revolutions as a spasm based on compassion untempered by a concern for liberty.

Crane Brinton, The Anatomy of Revolution (New York: Vintage Books, 1965). Brinton, more of a historian and less of a theorist than Arendt, soberly analyzes what the English, American, French, and Russian evolutions have in common.

Peter Gaunt, Oliver Cromwell (Oxford: Blackwell, 1996). This short biographical essay contains numerous quotations from his letters and speeches and is a good introduction to Cromwell's life and thought.

Thomas Paine, Common Sense (New York: Penguin Books, 1986). This, of course, is the book that made separation from England acceptable and even inevitable; first published 1776.

Richard Pipes, Three 'Whys' of the Russian Revolution, (New York: Vintage Books 1995). A short analysis of why the Tsar fell, Bolshevism succeeded, and Stalin succeeded Lenin.

David P. Szatmary, Shay's Rebellion (Amherst: The University of Massachusetts Press, 1980). A good short account of the 1780's farmers' insurrection in New England.

G.M. Trevelyan, The English Revolution 1688-1689 (New York: Oxford University Press 1965). A brief account of the peaceful revolution that undid the Catholic reaction to the Cromwellian revolution.