In the fall of 1777, Captain Patrick Ferguson, a Scottish marksman in the British army, had General George Washington in his sights near the Battle of Brandywine. If he had chosen to pull the trigger and killed Washington, he would not only have changed the course of the Revolutionary War, but of the new nation. But Washington had his back to Ferguson and was not on the battlefield, so Ferguson, in a moment of chivalry, did not shoot him. The story is recounted on Historynet.com, and in an essay by historian Thomas Fleming, “Unlikely Victory: 13 Ways the Americans Could Have Lost the Revolution” in “What If? — The World’s Foremost Military Historians Imagine What Might Have Been,” edited by Robert Cowley. Excerpt.