Addington County, Ontario
The county of Addington, situated within the Mecklenburg District, was originally created as an electoral district for the Legislative Assembly of Upper Canada in 1792 and its original limits were described as being:
bounded on the east by the westernmost line of the county of Frontenac, on the south by lake Ontario, to the westernmost boundary of the late township of Ernestown, and on the west by the easternmost boundary of the township of Fredericksburgh, running north thirty-one degrees west until it meets the Ottawa or Grand River, thence descending the said river until it meets the northwesternmost boundary of the said county of Frontenac, comprehending within the said county all the islands nearest to it, in the whole or greater part fronting the same.
Mecklenburg was renamed as the "Midland District" in 1792.
It was combined with Lennox County and Amherst Island in 1800 to become the incorporated counties of Lennox and Addington. The counties would regain their separate identities in 1845, but would continue to be united for electoral purposes. The newly surveyed township of Anglesea was added to Addington at that time. The township of Kaladar was also included, having been added to the incorporated counties in 1821.
At the beginning of 1850, Midland District was abolished, and the United Counties of Frontenac, Lennox and Addington replaced it for municipal and judicial purposes. In 1860, Lennox and Addington were formally amalgamated as the County of Lennox and Addington.
- Abinger Township - The township is now part of Addington Highlands.
- Amherst Island Township - The township is now part of Loyalist.
- Anglesea Township - The township is now part of Addington Highlands.
- Ashby Township - The township is now part of Addington Highlands.
- Camden Township - The township is now part of Stone Mills.
- Denbigh Township - The township is now part of Addington Highlands.
- Effingham Township - The township is now part of Addington Highlands.
- Ernestown Township - The township is now part of Loyalist.
- Kaladar Township - The township is now part of Addington Highlands.
- Sheffield Township - The township is now part of Stone Mils.
- Proclamation of July 16, 1792
- An act for building a gaol and court house in every district within this province, and for altering the names of the said districts, S.U.C. 1792, c. 8, s. 3
- An act for the better division of this province, S.U.C. 1798, c. 5, s. 15
- An Act for better defining the limits of the Counties and Districts in Upper Canada, for erecting certain new Townships, for detaching Townships from some Counties and attaching them to others, and for other purposes relative to the division of Upper Canada into Townships, Counties and Districts, S.Prov.C. 1845, c. 7, Sch. B
- An Act to repeal part of an Act passed in thirty-eighth year of His late Majesty's Reign, intituled, "An act for the better division of this province," and to make further provision for the division of the same into Counties and Districts, S.U.C. 1821, c. 3, s. 5
- An Act for abolishing the Territorial Division of Upper-Canada into Districts, and for providing temporary Unions of Counties for Judicial and other purposes, and for the future dissolutions of such Unions, as the increase of wealth and population may require, S.Prov.C. 1849, c. 78, Sch. A, B
- An Act to amend "An Act respecting the Territorial Division of Upper Canada", S.Prov.C. 1860, c. 39, s. 1