This politician initially gained prominence after founding a law practice with Joshua Reed Giddings, which he would use to win election as attorney for Ashtabula County. After his 1868 electoral defeat by Allen G. Thurman, this politician authored a report championing the annexation of Santo Domingo. This politician, who rose to power by defeating Thomas Ewing, may have distorted testimony by Daniel Sickles as Chairman of the Joint Committee on the Conduct of War. As (*) then-president pro tempore, this politician would have ascended to the presidency had Andrew Johnson been removed (10[1])from office. This politician nicknamed “Bluff” was the first namesake of an act that required Southern voters (10[1])to say that they had never supported the Confederacy, the Ironclad Oath. For 10 points, name this Ohio politician who names an 1864 bill with Henry Winter Davis. ■END■ (10[1])