On a warm October night in 1905, a respected banker stepped out of his office and into the darkness. Hours later, he would take his own life, leaving behind a handwritten confession and its most devastating line: "Andrews has worked my ruin." By morning, his bank had collapsed, taking the life savings of thousands of working people with it. Millions vanished. And the hidden machinery of the most corrupt, ruthless political empire in American history was instantly and violently exposed, confirming what had been whispered for years but never proven.

William "Bull" Andrews had spent decades learning the dark arts of power, as both the chief political operative of the Pennsylvania Republican machine. John D. Rockefeller's Standard Oil Company. Now, he wanted an empire of his own. Setting his sights on the far-flung Territory of New Mexico, the Bull saw a place raw enough to be shaped politically and rich enough to be mined economically. He would flood it with misappropriated capital, maneuver it toward statehood, and handsomely benefit when it gained inclusion in a nation changing under his feet. He had the party bosses, the railroad money, and had even placed a reluctant Theodore Roosevelt on a presidential ticket.

What Andrews hadn't counted on was the age that had built him was on borrowed time. In Washington, a new generation of progressive senators sought to block his path to statehood. In Pennsylvania, a charismatic small-town mayor built a campaign to destroy the machine that had built men like Andrews. Then, the banker walked into the darkness. When his confession became public, it handed his enemies exactly the weapon they needed. Filled with political intrigue, The Territory reveals how the Gilded Age came to an end—suddenly, and not at all.