Following distinguished Civil War service that took one of his legs and rendered an arm useless, General George R. Maxwell was sent to Utah Territory and charged - first as Register of Land, then as U.S. marshal - with bringing the Mormons into compliance with federal law. John Gary Maxwell's biography of General Maxwell (no relation) both celebrates an unsung war hero and presents the history of the longest episode of civil disobedience in U.S. history from the point of view of this young, non-Mormon who lived through it. With the onset of the Civil War, Maxwell volunteered for the First Michigan Cavalry and fought in most of the war's major battles in Virginia and at Gettysburg. In his subsequent service, Maxwell waged a different war as he battled the Mormon church's leadership over ownership of land, water, and timber. In the courts, in election outcomes, and in the legislature, Maxwell fought the Mormons' affirmation that God's law was superior to federal law. And as marshal, he was the first to properly conduct a federal trial in the Utah Territory, when John D. Lee was tried for the massacre of 120 Arkansas emigrants at Mountain Meadows. Gettysburg to Great Salt Lake recognizes Maxwell as both a bona fide Civil War hero and an unappreciated shaper of Utah history. His biography reveals this period through the eyes of a soldier and civil servant who embodied federal authority in Utah during its turbulent post-Civil War years.