The Revolution is Now Begun: The Radical Committees of Philadelphia. (I am glad to see that the University of Pennsylvania Press has issued a new edition of this classic). Ryerson's book first appeared in 1978, but it remains the best treatment of the complicated system of radical committees that were created in Philadelphia in the decade prior to independence.
The Revolution is Now Begun provided me with a good historical background to the revolution in Philadelphia, but it also confirmed my belief that the story of Presbyterians and the American Revolution needs to be told. Ryerson was sensitive to the role of Presbyterians in the Philadelphia Revolution, but only to a point. His book reminded me that Presbyterian politics in Philadelphia was much more dominant in the mid-1760s and in the immediate wake of the Revolution than it was between 1765 and 1776.
Having said that, Presbyterians still played an important role in the coming of the Revolution in Pennsylvania. Ryerson's book provided me with a cast of Presbyterian characters that I need to explore more fully. These characters include Benjamin Rush, David Rittenhouse, Robert Smith, John Bayard, William Bradford, Joseph Deane, Thomas Barclay, Peter Chevalier, Thomas McKean, James Mease, Charles Thomson, and Joseph Reed.
I am looking to supplement my reading of Ryerson with James Hutson's Pennsylvania Politics, 1746-70: Movement for Royal Government and its Consequences and Owen Ireland's Religion, Ethnicity, and Politics: Ratifying the Constitution in Pennsylvania. Stay tuned.