The Johnstown District was a historic district in Upper Canada which existed until 1849. It was created in 1798 from the Eastern District and consisted of the counties of:
The district town was originally Johnstown, but Elizabethtown, later Brockville, became the district town in 1808.
In 1822, Carleton County was separated to form the Bathurst District.
In 1838, parts of the Districts of Johnstown, Bathurst and Ottawa were separated to form a new Dalhousie District.
In 1849, the district was replaced by the United Counties of Leeds and Grenville.
References
Johnstown District, Upper Canada Wikipedia(Text) CC BY-SA