Brennan grew up in Shreveport, Louisiana and is a graduate of the United States Military Academy at West Point where he received a B.S. in Economics and was commissioned as an Aviation Officer. He graduated from flight school as an AH-64D Apache Pilot, and reported to Fort Bliss, TX where he served as a platoon leader and assistant operations officer. He is now stationed in Korea where he is the commander of A Co, 4-2 Attack Reconnaissance Battalion. He enjoys playing soccer, fantasy football, and hanging out with his wife, daughter, and Bernese Mountain Dog.