Frank Keegan was the protagonist and playable character of Medal of Honor: Vanguard.
After intense training in the United States and England, Keegan and his squad had fought through North Africa and survived the patriotic defense of the Vichy French forces.
At the invasion of Italy, codenamed Operation: Husky, Keegan and his squad parachuted into a small coastal village. Their C-47 was destroyed, but the entire squad miraculously survived. Upon landing, Keegan fought his way through a boathouse and reunited with Sgt. Magnusson. He continued the assault and reached a large house in the middle of the town. After waiting all night, the home came under attack from German soldiers. Keegan and the squad persevered and forced the enemy to retreat. The squad escaped the town and made their way to the target bunker. After heavy fighting, Keegan destroyed the bunker door and destroyed a trio of 28 cm SK/L45 coastal artillery cannons. After capturing the bunker, they moved 20 miles inland to join up with the rest of the division.
Training for Operation: Neptune required 82nd Airborne Division soldiers to be dropped off by trucks several miles from their base camp. They had to find their way back to the manor without getting lost. Keegan had broken his hand during one of the training missions, thus when the time came for Operation: Overlord, he was assigned to a glider drop. His glider's tow cable snapped and it crashed. Only Keegan and Cpl. Stephen Garrett survived. After an uphill struggle, they were joined by Pfc. Chalmers and Pfc. Pike. They fought through the village and reached a church. Sgt. Magnusson was trapped in here. After holding off the enemy soldiers, Keegan cut Magnusson loose. A Panzer attacked so they had to leave. Keegan went to open up the back door but was promptly bashed in the face by an enemy Falschirmjager. After waking up, he grabbed his gun and the squad set out to destroy several bridges. Keegan and a fellow paratrooper set out to collect bazooka pieces in order to destroy German armor in the area. They also rescued a trapped paratrooper in the process. He was nearly killed when an explosive set under a bridge detonated prematurely, killing his squadmate. He didn't come to until the next morning. Upon waking up, Magnusson was killed, putting Keegan in charge of the squad. He lead them through the village and to a battle at the final bridge. After capturing the bridge, he moved on to a mantion and defended it with bazookas from Panzer IV tanks. He was promoted to Sergeant after this.
Keegan and his squad were scheduled to take part in Operation: Market Garden. He was back in the C-53 and jumping. Upon landing in a small village, Keegan was tasked with destroying an anti-aircraft gun and securing a load of enemy intelligence documents hidden in the loft of the barn. After repelling an attack by a passing group of patrols, Keegan regrouped with the squad on the street and moved on to capture the bridge outside Grave. He destroyed an AA gun and easily captured the bridge. After destroying a final AA gun, Lt. McCollum arrived to greet Keegan and congratulate him on a job well done. Fighting in Grave was intense. Keegan destroyed an AA gun and a Tiger tank within the city before it was fully under American control, losing Chalmers in the process. Germany Keegan and his squad were folded into the 17th Airborne Division. The biggest drop in Keegan's life, he would be taking part in Operation: Varsity, an airborne drop into the fatherland. He was tasked with taking out several machine gun nests and Flak 88 cannons. During the battle, he was assigned to clear out the trench system, but was cut off from his squad after an explosion. He was reunited with members of his unit after intense lone wolf fighting throughout a factory. Afterwards, he was forced to go it alone again, in order to clear out a field full of snipers. He cleared the way for his team and fought through the factory remains and into the final area. The Germans launched a massive counterattack, but Keegan and his squad pulled through and held the factory.
- His favorite weapon is the M1 Garand rifle and later the Thompson M1928a1.
- He is the only character in Vanguard that can upgrade his own weapon, with the M1 Garand telescopic sight (M1C garand, adopted as a standard military sniper rifle in June 1944.) and the 50 round Thompson drum magazine.
- On the last level, he is called "Private", but he is no longer on that rank.
- Frank crosses paths with Jimmy Patterson and Boyd Travers in the franchise. During the participation in D-Day in France with Patterson, and in Sicily, France, Holland, and Germany with Travers.
- In Medal of Honor: Airborne, right after Boyd Travers jumping, Keegan' s falling plane can be seen with one of the engines burning.
- He is voiced by Yuri Lowenthal who has also voiced Pvt. 1st Class Ichiro Harry Tanaka and Sgt. Ybarra.
- He is the third playable character in the WWII Medal of Honor games in which he is not an OSS operative.