The Intrepid was a hydrogen gas balloon or aerostat built for use by the Union Army Balloon Corps

Union Army Balloon Corps

The Union Army Balloon Corps was a branch of the Union Army during the American Civil War, established by presidential appointee Thaddeus S. C. Lowe...

 for aerial reconnaissance purposes during the American Civil War

American Civil War

The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

. 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

Battle of Seven Pines

The Battle of Seven Pines, also known as the Battle of Fair Oaks or Fair Oaks Station, took place on May 31 and June 1, 1862, in Henrico County, Virginia, as part of the Peninsula Campaign of the American Civil War. It was the culmination of an offensive up the Virginia Peninsula by Union Maj. Gen....

.The fateful flight over the Battle of Fair Oaks was instrumental in saving the fragmented army of Union Army General Samuel P. Heintzelman

Samuel P. Heintzelman

Samuel Peter Heintzelman was a United States Army General. He served in the Seminole War, the Mexican-American War, the Yuma War, the Cortina Troubles, and the American Civil War, rising to the command of a corps....

 from what would have been sure defeat at the hands of the Confederates.