Which operation involved the U.S. military's first use of airborne troops during an invasion?

The operation that involved the U.S. military's first use of airborne troops during an invasion is indeed Operation Torch, which took place during World War II. This mission was executed in November 1942 and marked a significant moment in military history as it involved the deployment of airborne forces in an offensive capacity. The U.S. Army's 509th Parachute Infantry Battalion was used in this operation to secure key locations in North Africa, aiding the Allied forces in their efforts to take control of the region.

In the broader context of military operations, while other missions such as Operation Overlord introduced larger airborne operations, Operation Torch is particularly notable as it was the first instance where airborne troops were utilized in a combat invasion scenario by U.S. forces. This established a precedent for future military engagements, showcasing the effectiveness of airborne units in achieving strategic objectives quickly and efficiently.