Lauded for gallantry at Antietam and demoted for insubordination after Fredericksburg, Major General William Baldy Smith remains a controversial figure of the Civil War. His criticism of the Union high command made him unpopular with both peers and superiors. Yet his insight as an officer and an engineer enabled him to offer effective solutions to challenges faced by fellow generals. In this first comprehensive biography, Smith emerges as a field commander with deep concern for his men and a fearless critic of the failures of the Union generalship, who was recognized for a strategic perspective that helped save Federal armies.