The members of the Senate were elected every two years by the legal voters of the State, which was apportioned every four years, the number of Senators being fixed by the Legislature according to the enumeration of white male inhabitants over twenty-one years of age, and the districts established accordingly. In the First General Assembly (1803), Ross County, which then embraced the present counties of Franklin and Madison, composed a Senatorial district. In the Second and Third (1803-04 and 1804-05) Ross and Franklin were together, this territory being a portion of the latter county, while in the Fourth (1805-06) Highland County was attached thereto and remained so throughout the two subsequent Assemblies. In the Seventh and Eighth (1808-09 and 1809-10), Franklin and Delaware formed a district. The Ninth General Assembly (1810-11) is the first time we find the name of Madison figuring as a portion of a Senatorial district, composed of Franklin, Delaware, Madison and Pickaway; while in the Tenth (1811-12), Pickaway was put into another district, and the others remained together until the Nineteenth General Assembly (1820-21), when the new county of Union formed a part thereof. Thus it remained until the Twenty-second Assembly (1823-24), at which time Marion and Crawford Counties were attached to this Senatorial district, which then read Franklin, Madison, Union. Delaware, Marion and Crawford. This lasted, however, only through that one session, and in the Twenty-third (1824-25), the three latter counties were cut off from this district, which existed as Franklin, Madison and Union up to the Twenty-seventh Assembly (1828-29), when Madison, Logan and Shelby constituted a district. The following session, Union County was added thereto and remained as such until the Thirtieth Assembly (1831-32), at which time Madison, Union, Logan, Shelby and Hardin were united. In the succeeding session, Shelby County, was replaced by Hancock. In the Thirty-fifth (1836-37), another change occurred, Madison, Fayette and Greene forming a district, existing thus four years, when the district was again changed. In the Thirty-ninth General Assembly (1840-41), Franklin, Madison and Clark were combined and remained united up to and including the Forty-sixth session (1847-48), but in the Forty-seventh, Franklin County was replaced by Champaign, so that Madison, Clark and Champaign were together at the time of the adoption of the new constitution in 1851, which provided that the Senatorial apportionment was to be established decennially, and obtained by dividing the whole population of the State by thirty-five, the quotient thereof to be the ratio of Senatorial representation. The State was divided into fixed districts, which were numbered, and these three counties have since constituted the Eleventh Senatorial District of Ohio.
The following is the list of Senators with their date of service: 1803, Nathaniel Massie, Abraham Claypool; 1803-04, Abraham Claypool. Nathaniel Massie, John Milligan; 1804-05, Abraham Claypool, Joseph Kerr; 1805-06, Joseph Kerr, Duncan McArthur; 1806-07 and 1807-08, Duncan McArthur, Abraham Claypool; 1808-09, 1809-10, 1810-11 and 1811-12, Joseph Foos; 1812-13 and 1813-14, John Barr; 1814-15 and 1815-16, Joseph Foos; 1816-17 and 1817-18, Thomas Johnson; 1818-19, 1819-20, 1820-21 and 1821-22, Joseph Foos; 1822-23, Henry Brown; 1823-24, James Kooken 1824-25, 1825-26, 1826-27 and 1827-28, Joseph Foos; 1828-29 and 1829-30, William Fielding; 1830-31 and 1831-32, John Shelby; 1832-33 and 1833-34, Philip Lewis; 1834-35 and 1835-36, Samuel Newell; 1836-37 and 1837-38, John Avbuckle; 1838-39 and 1839-40, Aaron Harlan; 1840-41 and 1841-42, Alexander Waddle; 1842-43 and 1843-44, Joseph Ridgeway, Jr.; 1844-45 and 1845-46, Alfred Kelley; 1846-47 and 1847-48, Jennet Stutson; 1848-49, 1849,-50 and 1850-51, Harvev Vinal; 1852-54, John D. Burnett; 1854-56, Henry W. Smith; 1856-58, Joseph C. Brand; 1858-60, Saul Henkle; 1860-62, Richard A. Harrison; 1862-64, Samson Mason; 1864-66, A. P. Howard; 1866-68, Toland Jones; 1868-70, J. Warren Keifer; 1870-72, Aaron P. Howard; 1872-74, Wm. Morrow Beach; 1874-76, Alexander Waddle; 1876-78, W. R. Wamock; 1878-80, George W. Wilson; 1880-82, Thomas J. Pringle.