William Dennison , Jr . William Dennison , Jr . ( November 23 , 1815 – June 15 , 1882 ) was a Whig and Republican politician from Ohio . He served as the 24th Governor of Ohio and as U . S . Postmaster General in the Cabinet of President Abraham Lincoln during the American Civil War . Early life and career . Born in Cincinnati , Dennison graduated from Miami University , studied law , and was admitted to the Ohio bar in 1840 . A canny businessman , he led the Exchange Bank and the Columbus and Xenia Railroad , and organized the Columbus and Hocking Valley Railroad , while becoming active in politics . In 1840 , he married Anne Eliza Neil , the daughter of the wealthy Columbus businessman William Neil , whose farm later became the campus of Ohio State University . Together , William and Anne Dennison had seven children . The eldest of them was a son , William Neil Dennison , who later won distinction in the Civil War while serving in the U . S . Horse Artillery Brigade . William Dennison , Jr . , was one of the first major Ohio politicians to leave the dying Whig Party for the new Republican Party . He rose quickly through the party ranks due to his anti - slavery and anti - discrimination efforts in the Ohio State Senate . Dennison was elected to the governorship in 1859 , defeating Rufus P . Ranney , and served a single term from 1860 to 1862 . Before the outbreak of the American Civil War , he refused the demands of Kentucky and Virginia state authorities for the extradition of fugitive slaves or the punishment of those who helped them . Civil War . He organized Ohio ' s mobilization in the opening days of the war , and was generally effective , despite having a small staff and no prior military experience . His efforts led to the creation of several large training camps for newly raised troops , one of which would be named for him ( Camp Dennison ) . Dennison tried but failed to be elected to the United States Senate in 1861 , when he was defeated by John Sherman . Without being asked by the War Department , he sent Ohio troops under George McClellan into western Virginia , where they guarded the Wheeling Convention , which eventually led to the admission of West Virginia as a free state . He also took the initiative to seize control of Ohio ' s railroads and telegraph lines early in the war to allow military usage , angering Peace Democrats in the Ohio Legislature . He denounced secession and Ohio ' s " Copperheads " , established a consistent supply of arms and equipment for the new troops , and was a vocal supporter of Lincoln ' s policies . During his term , he raised over 100 , 000 troops and organized 82 three - years regiment s for the Union army . However , errors by the Governor and his subordinates led the state ' s alliance of Republicans and War Democrats to drop Dennison as a candidate in 1862 . The parties turned instead to David Tod , a War Democrat . Historian Richard H . Abbott wrote , " No Ohio chief executive [ before Dennison ] had ever exercised such powers and fulfilled such duties with a greater sense of public responsibility and determination . Nevertheless . . . politics dictated his demise . " Dennison accepted this turn of events with good grace , capably advised his successor , and provided valuable services in helping recruit black troops for Ohio units . He served as Chairman of the Republican National Convention in 1864 . He was appointed U . S . Postmaster General by President Abraham Lincoln , and served from 1864 to 1866 , leaving the Cabinet after he decided he could no longer support the policies of President Andrew Johnson . Postbellum career and memorialization . After the war , Dennison served on the Columbus City Council and organized the Franklin County Agricultural Society . President Ulysses S . Grant appointed him the first President of the Board of Commissioners for the District of Columbia , the highest governing office of Washington , D . C . , in which Dennison served from 1874 to 1878 . He sought the Republican nomination for the U . S . Senate in 1880 , but was defeated by James Garfield . Dennison remained active in state and national politics until his death . He left behind a widow and seven children , and was buried in Green Lawn Cemetery , Columbus , Ohio . Of Dennison ' s single term in the opening stages of the Civil War , historian John S . Stilt wrote , " His wisdom and foresight were appreciated by few and condemned by many . . . It is doubtful whether any of his predecessors could have met the issues any more successfully . " Camp # 1 of the Department of Ohio of the Sons of Union Veterans of the Civil War is named for Governor William Dennison . It was chartered August 1 , 1882 , shortly after Dennison ' s death at age 66 .