Who organized the Balloon Signal Service for the Union Army?

Thaddeus S. C. Lowe is the correct choice as he played a pivotal role in organizing the Balloon Signal Service for the Union Army during the American Civil War. Lowe, who was an aeronaut and inventor, recognized the potential of ballooning for military reconnaissance. He proposed the idea of using hot air balloons for observation, which was accepted by the Union Army in 1861.

Lowe’s efforts led to the establishment of the Balloon Corps, a key development in aerial reconnaissance that allowed the Union to gather crucial intelligence on enemy positions and movements from above. His innovations in using balloons for military purposes laid the groundwork for future military aviation strategies and highlighted the importance of aerial observation in warfare.

The other individuals listed, while significant in the field of aviation, did not have a direct involvement in the establishment of the Balloon Signal Service. Their contributions came in different contexts, such as Zeppelin with dirigibles and airships, Da Vinci with conceptual designs for flight, and Lilienthal with pioneering glider flights.