All of what is now Franklin County, NY, was once a part of either the Old Military Tract or Macomb's Purchase. The towns of Burke, Chateaugay, Bellmont, and Franklin were part of the Old Military Tract, created in 1786 to set aside land for veterans of the Revolutionary War. The other 15 towns were a part of Alexander Macomb's purchase from New York State of nearly four million acres of land in 1791. The land was subdivided to landowners with names now familiar by the towns named after them: William Constable, Michael Hogan, James Duane and others. As late as 1853 the map of Franklin County included unsettled townships with names such as 'Killarney' and 'Gilchrist' that later were absorbed into other towns. The county is now comprised of 19 towns and 6 villages.
Franklin County was created in 1808 from Clinton County, when it became obvious that travel to Plattsburgh to conduct legal business was too great a burden. The county seat was set in Malone, as early settlement was primarily in the northern portion of the county. The largest period of growth in the county was between 1820 and 1830, when the population nearly tripled.
The earliest industry in the county was potash production. Potash was created by felling trees, burning them in great piles, leaching the ashes, and boiling the lye to dryness. The making of potash was also a way to dispose of the large amount of timber created when clearing land for farms, roads and houses. Once roads were carved into the great forest lands, logging became a profitable industry. Great tracts of trees were cleared and the logs hauled to rivers and floated out of the wilderness.
Other early industries included agriculture, especially the raising of hops (mainly used to brew beer) and potatoes, mills, and iron ore mining. The southern portion of the county benefited from the founding of sanatoriums for the treatment of tuberculosis and other ailments, based on the work of Dr. E.L. Trudeau. The open-air 'rest cure' made the Adirondacks and the Saranac Lake area nationally famous. The Adirondacks, which were once a barrier to settlement, began to serve as a draw for tourists in the late 19th century, and now serve as one of Franklin County's defining features.