Frank Pierce is the main villain of the 1967 Western movie The War Wagon.
He was portrayed by the late Bruce Cabot who also played Bert Saxby in Diamonds Are Forever.
Taw Jackson, the hero and rancher, makes his arrival back to his hometown to get payback on Pierce, the villain and businessman, who framed and sent Jackson to prison 3 years before. Pierce finds gold on Jackson's land and mines and sells the gold. When Pierce learns that Jackson has been released from prison because of good behavior and plans to steal a gold shipment, he sends 2 of his henchmen to hire Lomax, an assassin and villain turned good, to kill Jackson.
Jackson hires Lomax because of his great gun skills and safe cracking skills and knows Lomax worked for Pierce and helped in sending Jackson to prison. Later Pierce tries to hire Lomax to destroy Jackson and offers to pay him a lot of money if he does it, which Lomax says he'll think about it and he'll do it when he's ready. Pierce transports the gold in a heavily armored and impregnable stagecoach known as The War Wagon, with a large Gatling gun mounted on top of it and guarded with armed men, in front and behind. Pierce runs the town and says he wants everything to be legal with everything he does.
Later when Jackson and the heroes steal the gold from the war wagon, Pierce is killed in a shootout when one of his minions tries to escape. Then The War Wagon crashes into a ravine.