The Eastern Townships is a huge section of Quebec, strung out along the American border, basically beginning at Lake Champlain. It stretches as far eastwards as the Quebec-Maine border (not far from the Chaudiere River) and as far north as Drummondville. It's made up of all the land south of the St. Lawrence River which was not granted under the French seigneurial system.

           Technically, a small strip of land on the south west corner of this region, known as the Seigneury of St. Armand, (located directly under the townships of Stanbridge and Dunham) is not a part of the Townships, but for genealogical purposes most people lump it in with the rest of the Townships because it was settled by the same type of people.

           The Eastern Townships was opened up for settlement by the British in the early 1790's. The more southerly regions tended to be settled primarily by Americans from the New England states, the more northern regions by immigrants from the British Isles. A wave of French-Canadian settlers swept into the region in the 1840s and by the 1871 census French-Canadians made up the majority of the population of the Townships.

           As the name implies, the region (now called the Estrie) was organized by townships which were then grouped into counties for administrative purposes.

          As the population of the Townships grew, place names, county names and the groupings of townships within counties changed. However, the name of each Township remained constant, so always make a note of the Township as well as the village or town in which your ancestor lived and use that as your geographic anchor.

 For example, I live in Sutton Township. In the 1825 census it is in Richelieu County, up until the 1851 census it is in Missisquoi County and after that census it is in Brome County. The one geographic constant is the township's name.

           Near me, in Potton Township, is the village of Dunkin. Early church records refer to it as West Potton. The village of Highwater, not far from Dunkin, was once called Mansonville Station (confusing, since the town of Mansonville is not far from Highwater.)

           Here's an alphabetic lists of the townships included in the Eastern Townships with their modern county groupings:
 
 

Adstock (Megantic Co.) Adstock (Frontenac Co.) Arthabaska (Arthabaska Co.) Ascot (Sherbrooke Co.) Auckland (Compton Co.)  Aylmer (Frontenac Co.) Barford (Stanstead Co.) Barnston (Stanstead Co.) Bixborough (Frontenac Co.) Bolton (Brome Co.)  Brome (Brome Co.)  Brompton (Richmond Co.) Broughton (Megantic Co.) Bulstrode (Arthabaska Co.) Bury (Compton Co.) Chesham (Frontenac Co.) Chester (Arthabaska Co.) Cleveland (Richmond Co.) Clifton (Compton Co.) Clinton (Frontenac Co.) Colraine (Megantic Co.) Compton (Compton Co.)  Ditchley (Frontenac Co.) Ditton (Compton Co.)  Dorset (Frontenac Co.) Dudswell (Wolfe Co.) Dunham (Missisquoi Co.) Durham (Drummond Co.) East Farnham (Brome Co.)  Eaton (Compton Co.)  Ely (Shefford Co.) Emberton (Compton Co) Forsyth (Frontenac Co.) Garthby (Wolfe Co.) Gayhurst (Frontenac Co.) Granby (Shefford Co.) Grantham (Drummond Co.) Halifax (Megantic Co.)  Ham (Wolfe Co.) Hampton (Compton Co.) Hereford (Compton Co.) Horton (Arthabaska Co.) Inverness (Megantic Co.) Ireland (Megantic Co.)

Kingsey (Drummond Co.) Lambton (Frontenac Co.) Leeds (Megantic Co.) Lingwick (Compton Co.) Marlow (Frontenac Co.)  Melbourne (Richmond Co.) Milton (Shefford Co.) Nelson (Megantic Co.)  Newport (Compton Co.) Orford (Sherbrooke Co.) Potton (Brome Co.)  Price (Frontenac Co.) Roxton (Shefford Co.)  Shefford (Shefford Co.)  Shipton (Richmond Co.) Simpson (Drummond Co.) Somerset (Megantic Co.) South Ham (Wolfe Co.) Spalding (Frontenac Co.) Stanbridge (Missisquoi Co.)  Stanfold (Arthabaska Co.) Stanstead (Stanstead Co.) Stoke (Richmond Co.) Stoke (Richmond Co.) Stratford (Wolfe Co.) Stukely (Shefford Co.)  Sutton (Brome Co.)  Thetford (Megantic Co.) Tingwick (Arthabaska Co.) Warwick (Arthabaska Co.) Weedon (Wolfe Co.) Wendover (Drummond Co.) West Bury (Compton Co.) West Farnham (Missisquoi Co.) Whitton (Frontenac Co.) Wickham (Drummond Co.) Windsor (Richmond Co.) Winslow (Frontenac Co.) Woburn (Frontenac Co.) Wolfeson (Wolfe Co.) Wotton (Wolfe Co.)