The Interior Department under Secretary Columbus Delano, whom Grant appointed to replace Cox, was rife with fraud and corruption, with the exception of Delano's effective oversight of Yellowstone, and Delano was forced to resign. Surveyor General Silas Reed had set up corrupt contracts that benefited Delano's son, John Delano. Grant's Secretary Interior Zachariah Chandler, who succeeded Delano in 1875, implemented reforms, fired corrupt agents, and ended profiteering. When Grant was informed by Postmaster Marshall Jewell of a potential Congressional investigation into an extortion scandal involving Attorney General George H. Williams' wife, Grant fired Williams and appointed reformer Edwards Pierrepont in his place. Grant's new cabinet appointments temporarily appeased reformers.