The last town in colonial Connecticut to be settled. Colebrook was named after a town in Devonshire, England. The reason is now unknown. The year 1765 saw Benjamin Horton, leader of a trickle of settlers, arrive amid virgin forests. Samuel Rockwell, among those who shortly followed two years afterward, built one of the outpost's first houses. Here before long was born Colebrook's first child, a boy who parents fittingly named him Alpha.

Iron forges soon developed, ore being drawn by oxen from Salisbury for smelting with the plentiful local wood. Cannon for use in the Revolution were made and lugged where needed. A story connects one of those with the piece on exhibit in Quebec whose label states "Taken by the British at Bunker Hill."

Notable structures from the past crowd about this marker. Northward on the left is the Samuel Rockwell House (1767); below it is the Colebrook Store (1812), a Greek Revival gem and a federally registered historic building.