"John Frémont’s 100 Days" by Gregory Wolk is the first book-length study of John Frémont’s time in Missouri written since the Civil War. For 100 days in 1861, Frémont was the general in charge of the US Army’s Western Department. Frémont arrived at his St. Louis headquarters in late July, setting into motion three tumultuous months that would see him declare martial law; emancipate two enslaved men; and give rise to one of the Civil War’s most respected figures, Ulysses S. Grant.