Afterwards he worked a short assignment with the Union Army Balloon Corps.

Eventually he was chosen over other candidates to be chief aeronaut of the newly formed Union Army Balloon Corps.

Furthermore, the Union Army Balloon Corps, which had performed the only aerial observation during the Peninsula Campaign, was now joined by a Confederate competitor.

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.

As the armies dug in, Union Army Balloon Corps aeronaut Professor Thaddeus S. C. Lowe used two balloons, the Constitution and the Intrepid, to perform aerial observation.

Upon returning home he was summoned by Secretary of the Treasury Salmon P. Chase to bring his balloon to Washington, D.C. Lowe ended up as Chief Aeronaut of the Union Army Balloon Corps, which all but ended any idea of his making a transatlantic flight.