Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| District | Incumbent | Party | First elected | Result | Candidates |
| --- | --- | --- | --- | --- | --- |
| Ohio 7 | Samuel Shellabarger | Republican | 1864 | Retired Republican hold | James J. Winans (R) 50.2% John H. Thomas (D) 49.8% |
| Ohio 8 | John Beatty | Republican | 1868 (s) | Re-elected | John Beatty (R) 52.0% John H. Benson (D) 48.0% |
| Ohio 10 | James M. Ashley | Republican | 1862 | Lost Re-election Democratic gain | Truman H. Hoag (D) 51.5% James M. Ashley (D) 48.5% |
| Ohio 11 | John Thomas Wilson | Republican | 1866 | Re-elected | John Thomas Wilson (R) 54.2% John Sands (D) 45.8% |
| Ohio 16 | John Bingham | Republican | 1864 | Re-elected | John Bingham (R) 50.8% Josiah M. Estep (D) 49.2% |
Question:
When was incumbent John Thomas Wilson first elected? 
Answer:
1866.0