From 1788-1841 local affairs in each district of Upper Canada were administered by the district court of General Quarter Sessions of the Peace, composed of magistrates appointed by the Governor or Lieutenant Governor in council. These Justices of the Peace met four times a year to try legal cases and supervise the administration of the area.

In 1841, the District Council’s Act, whereby a District Council assumed the administrative powers of the magistrates of the Quarter Sessions, effective 1 January 1842, changed this system. However, the Brock District was formed two years prior to the instituting of District Councils for local self-government, so that the Brock District Court of Quarters Sessions of the Peace administered the earliest affairs of Brock District (1840-1841).

Each District Council was composed of a warden, councillors, clerk, district treasurer, surveyor and two auditors. The Governor appointed all members with the exception of the elected councillors.

District Councils were given jurisdiction over roads, bridges, district real estate, sales, administration of justice expenses, the establishment and maintenance of schools, the fixing of district officers’ salaries, and the salaries and fees of township officers. All by-laws passed by a district council had to be submitted to the Governor in Council and might be disallowed within thirty days.

The first District Council of the District of Brock, met in the Court House, Woodstock, on Tuesday, the 8th day of February, 1842, pursuant to the Act 4th and 5th Victoria, Chapter 10th, by which Act a meeting of the Council was to be held on the second Tuesday of the months of February, May, August and November; and where no meeting was to be longer then six days. Beginning in 1846 this was changed, with council meeting twice a year, commencing on the first Tuesday in the months of February and October. Such meetings were not to be held for a period longer than nine successive days. As previously mentioned, the Governor was to appoint the Warden, Treasurer and Clerk. While each Township was to elect one Councillor, and the Townships which had more than three hundred freeholders and householders on the assessment list, were to elect two.

The District of Brock was made up of the following municipalities:

        Blandford       Oakland
        Blenheim        East Oxford
        Burford         North Oxford
        Dereham     West Oxford
        Nissouri            Zorra
        Norwich

Wardens for the district of Brock were:
1842 The Hon. Peter Boyle de Blaquire
1843 Solomon Lossing (appointed in April)
1844 Solomon Lossing (February session)
1844 Benjamin Van Norman (May, August and November Sessions)
1845 George W. Whitehead (August and November Sessions)
1846 George W. Whitehead
1847 Jared Vining
1848 Jared Vining
1849 William Carroll

Other appointees were:
1842 – 1849 Clerk – William Lapenotiere
1842 – 1849 Treasurer – H.C. Barwick
1842 – 1845 Surveyor – James Cull
1846 – 1849 Surveyor – O. Bartley
1844 – 1845 Supt. of Schools – Rev. N. Bosworth
1846 Supt. of Schools – George Hendry
1847 – 1849 Supt. of Schools – Rev. Wm. H. Landon
1839- District Court Clerk – John George Vansittart
1839- Surrogate Court Registrar – John George Vansittart
1839- District Sheriff – James Carroll
1839- District Judge – John Arnold

In 1846, in response to continued agitation for a more democratic structure for the District Council, important changes were made to the Act of 1841. Positions previously appointed by the Governor were now to be appointed by the District Councils. Councils were also permitted to pay members for services. In addition, the School Act was amended; it provided for Superintendents of Education to be appointed by District Councils and for the Superintendents to be invested with considerable administrative powers.

In 1849, the Municipal Corporations Act, better known as the Baldwin Act (named after the politician Robert Baldwin), established counties as units of local government, thus providing for the composition of county councils and their responsibilities. The Baldwin Act became effective 1 January 1850 and remained in effect until its repeal by the Municipal Act, 2001, effective 1 January 2003. With the Baldwin Act in place, the District of Brock became the Incorporated County of Oxford. The Municipality of Nissouri was split with West Nissouri becoming part of Middlesex County, and in the east, Burford and Oakland Townships were removed to Brant County.