Though Fred volunteered immediately after Pearl Harbor, he didn't actually leave for basic training until March 24, 1942.  The military was far from ready to quickly process and train the thousands who came forward after Pearl Harbor.  This ultimately worked to his benefit as requirements of a college degree to attend Officer's Training School had been waived by the time he entered service.  Fred Hillis, then a college Junior, and 95 other Army Air Corps enlistees from Missouri were shipped to Uvalde, Texas for basic training.  This was soon followed with flight schools at Kelly Field and Randolph Field outside San Antonio.

Fred had never been very far from his home, St. Louis.  There was an occasional visit back to family in Southern Missouri, but that was it for him and for most of the young men who found themselves hundreds of miles away in Texas.  Basic training was his first taste of the rest of the world.  He loved it all, Texas, his new found friends, and flying, but most of all flying.  What freedom, exhilaration, beauty.  His letters home to his sweetheart Mary were full of his friends, the glory of flying and his adventures in the sky.  Phone calls and letters flew between the two.  Mary made the long train trip to San Antonio for a visit and arrangements were made for a November wedding after he earned his wings.  On November 8, 1942 Fred and Mary were married in San Antonio, Texas.  The next day his active duty officially commenced.  Captain Hillis received orders to report to Eglin Field in Florida.

Any flying was great, as far as Fred was concerned.  He did extremely well at Eglin Field, and soon found himself first an instructor and then a medium bomber test pilot in the Proving Ground Group at Eglin.  He flew the North American B-25 and Martin B-26 twin-engine bombers. He wasn't satisfied with just being the best bomber pilot he could be.  He grabbed the chance to fly everything Eglin Field had to offer, often wandering over to the fighter section to bum fighter time (later recalled by friend and fellow pilot, Colonel Bert McDowell).  It wasn't long before he had finally made it to the Bell P-39 Airacobra, even though it meant leaving the parachute behind to fit into the aircraft.   Tall and lanky with an insatiable appetite and uncontrollable hair, it was no wonder that Fred was tagged "Dagwood" by his fellow pilots.  But for once Fred's height worked to his disadvantage.  It seemed inevitable that his desire to fly fighters in combat would be thwarted by height restrictions.  Fighter pilots had to be small enough to easily bail out of the cockpit in an emergency.  Getting in and out of a fighter cockpit for Fred Hillis was never a quick or easy task.

Fred and Mary soon settled into the routine of life in Florida.  The heat, humidity and world-class bugs were tempered by the excitement of their new life together and the new life growing within Mary.  A daughter, Cynthia, was born at the Eglin Field hospital on September 9th, ten months after their wedding.  As one of three boys, Fred was not at all disappointed to have a daughter.

Nobody really knows how he did it, but somehow Fred finally managed to pass the physical examination to become a fighter pilot.  At 6’3”,according to regulations, he was too tall to fit comfortably in fighter cockpits. But he couldn't wait to get out of the teaching and testing business and into combat . . . . . and he must have had a doctor friend at Eglin. In early August of 1944 he received orders transferring him overseas where he was to join the 9th Army 366th Air Corps.  He soon found himself in France flying the Republic P-47 Thunderbolt.  He christened his first fighter "Cookie," a nickname given his daughter by his fellow test pilots at Eglin Field. Afterward he finally managed to shake the Dagwood moniker, but daughter Cynthia was destined to carry her nickname Cookie for life.