In June, 1861, Thaddeus Lowe demonstrated hot air balloons to Lincoln for use in the military. Lowe was from New Hampshire, and was the son of a cobbler. After attending a chemistry lecture he was so interested that the professor took him on as an assistant. After the professor retired, he traveled around the country giving his own lectures. He also began making hot-air balloons, and by 1860 he began a leading ballon builder in America. He planned to fly across the Atlantic ocean, and so he tried a test flight from Cinncinati to Washington, DC. His plans did not go very well however. He ended up in South Carolina, a few months after they seceded. He was arrested for a time, but finally was allowed to go home.
With the Civil War at hand, Lowe abandoned the idea of crossing the ocea. Instead he proposed to Abrahamin Lincoln that his ballons be used for aerial reconisance. He was sucessful, and after his performance at the Battle of Bull Run a ballon corps was formed with Lowe at the head. 

Mobile Inflation of the Balloons