I had hoped Phillips' 1775 would be a sort of prequel to David McCullough's excellent 1776, but it is actually something else entirely. Phillips delves deeply into the causes of the American Revolution, focusing particularly on the economic and religious factors instead of the ideological factors that get most of the attention in popular histories of the war. The title references Phillips' thesis that the war was well underway by 1775. Most histories use the signing of the Declaration of Independence in 1776 to mark the start of the revolution, but while the Declaration was an important political document fighting had already begun by 1775 in New England and in the Carolinas between patriots and loyalists. By 1775 only 2 of the 13 colonies were actually being governed by their British appointed governors, most of the others having been forced to flee for their own safety. The local militias were entirely dominated by patriots. The British were in fact attempting to recapture territory of which they had already lost control.
Phillips spends a fair amount of time on Benedict Arnold's failed invasion of Quebec in 1775. He points out how close Arnold came to success and how his actions forced the British to waste precious troops defending Canada against a second attack that never came. He also spends quite a bit of time discussing the political machinations of Samuel Adams, a topic which is often ignored. Phillips argues that Adams may have manipulated the British into concentrating their forces in Boston which was arguably the worst possible location. Boston had a high concentration of patriots and a port that froze in the winter trapping the British fleet in hostile territory. If the English had concentrated their forces at New York they might have found a much friendlier populace and been able to cut off New England from the southern colonies by controlling the Hudson River.