Tap in “Bunker Hill Charlestown” and you’ll be directed to...that other hill. To Philbrick, this enduring confusion is emblematic of the Bunker Hill story. “The whole thing’s a screw-up,” he says.

NEW YORK — As the U.S. marks the 250th anniversary of the Battle of Bunker Hill, it might take a moment — or more — to remember why. Start with the very name. “There's something percussive about it: ...