The Intrepid was a hydrogen gas balloon or aerostat built for use by the Union Army Balloon Corps for aerial reconnaissance purposes during the American Civil War. It was one of seven balloons constructed for the Balloon Corps and was one of the four larger balloons designed to make ascensions to higher elevations with a larger lift capacity for telegraph equipment and an operator. It was the balloon of choice for Chief Aeronaut Thaddeus Lowe overlooking the Battle of Fair Oaks.