History of the Eastern Townships, by C. M. Day
Pub. 1869, Reprinted, 1992, Pages 292-293
A tract of land lying within the district of Montreal, containing 57,252 acres, 3 roods, and 30 perches, bounded north by Farnham, east by Brome and Sutton, south by St. Armand, and west by Stanbridge, was erected into a township named Dunham. The petition for this grant was dated April 28th, 1795; the warrant of survey issued August 27th of the same year; and in 1795, the township was granted to Thomas Dunn and his associates, viz., Josseph Buck, John Heliker, Jacob Heliker, George Saxe, Mathew Hall, William Ferrand, David Ferrand, Joshua Chambers, Amos Woodland, David Reychart, John Clark, Thomas Best, Daniel Mills, Jeremiah Reychart, Daniel Trever, Alexander McDougall, Thomas Pell, Andrew Ten Eyck, Henry Ten Eyck, Archibald Henderson, Henry Hall, Elisha Dickinson, Jacob Best sen., George Waymore, Abraham Lampman, John Mills, Stephen Jenner, Jacob Best jun., Adam Deal, Frederick Streit, Samuel Mills, Philip Ruiter, and Jacob Ruiter.
It is said that Dunham was the first township erected in Lower Canada. Among the earliet inhabitants if not the very first to locate within its limits, was Andrew Ten Eyck from New Jersey, who settled in the south-western part of the tract, in 1793. He was a U. E. Loyalist, and came to Canada as the forerunner of a numerous influx of the same class of settlers."
Eastern Townships Map
This map shows "roughly" what townships fell into what counties about 1871. A friend maintains the Eastern Townships site for RootsWeb, and gave me permission to copy here. "My area" is colored in tan, located at the lower left side, just above Vermont.