On June 1, 1862, Thaddeus Lowe floated above a fierce Civil War battle in a silk hydrogen balloon. From the wicker basket dangling a thousand feet above ground, he telegraphed a message to Northern generals on the ground: Union troops were finally driving back the Confederate forces. Lowe's message was transmitted to the War Department in Washington, where President Abraham Lincoln read his flying spy's good news with relief. For two years during the Civil War, a corps of balloonists led by Thaddeus Lowe spied on the Confederate army. They counted rebel soldiers, detected troop movement, and directed artillery fire against enemy positions. Lowe and his aeronauts provide valuable intelligence to the Union army, even after the balloons became targets of Confederate shooters and saboteurs. Using Civil War photographs and primary sources—including Lowe's papers in the Library of Congress and the writings of Confederate and Union soldiers—Jarrow reveals the dangers, personality clashes, and other challenges faced by the nation's first air force in this Voice of Youth Advocates Nonfiction Honor List book.