One of the main themes that Ketchum brings home -- a theme common to all good histories that practice "thick description" -- is how contingent the outcome of the battle was. If the British had not sent over the wrong size ammunition for their artillery at first, or if the tide had allowed the British to land earlier, the Americans probably would have been cleared off the hill in short order. If the Americans had had just one resupply of powder from the rear, they might have held the hill and driven the British back.
Along with Fischer's Paul Revere's Ride and Galvin's The Minute Men, this is one of the best works I have read on the opening of the American Revolution.
I learned a lot about the battle, and feel that I have a much better understanding, and appreciation for what took place on that fateful afternoon. I highly recommend it to anyone interested in the battle, or learning more about the men who fought the Revolution, and the odds they faced.
My only complaint about the book is the lack of a good map of the area. Ketchum uses contemporary drawings of Boston to show the places he is describing, but these are not very accurrate and you never really get a picture of where the battle took place in relation to other landmarks. However, this does not detract from the narrative, and I strongly reccommend reading this book, for anyone of any level of interest in the era.
