The discovery of Robert E. Lee’s Special Orders No. 191 outside of Frederick, Maryland, on September 13, 1862, is one of the most important and hotly disputed events of the American Civil War. For more than 150 years, historians have debated if George McClellan, commander of the Union Army of the Potomac, dawdled after receiving a copy of the orders before warily advancing to challenge Lee’s forces atop South Mountain.

In The Tale Untwisted, authors Gene Thorp and Alexander Rossino document in exhaustive fashion how “Little Mac” in fact moved with uncharacteristic energy to counter the Confederate threat and take advantage of Lee’s divided forces, seizing the initiative and striking a blow in the process that wrecked Lee’s plans and sent his army reeling back toward Virginia.

This study is a beautifully woven tour de force of primary research that may well be the final word on the debate over the fate and impact of the Lost Orders on the history of the 1862 Maryland Campaign.