Lewis Thornton Powell, alias Payne. Powell, one of Booth’s co-conspirators in the assassination plot against Lincoln and members of his government, was an Alabama native, who was living with his family near Live Oak, Florida, when the war began. His mission in the plot was to kill Secretary of State William H. Seward. Powell severely wounded Seward and several others at the secretary’s home. Soon after fleeing the scene of his crime, Federal authorities arrested Powell. On July 7, 1865, Powell was executed along with three of the other conspirators.