Fort Klock is an excellent, little altered architectural example of a mid-18th century fur trading post and fortified stone house structure that was used in the Mohawk Valley of Upstate New York. It served as a place of refuge during the French and Indian War and later during the American Revolution. The site was chosen well by Johannes Klock for it advantages for trading and defense purposes. A sheltered cove laid directly below the fort and provided a safe anchorage for the bateaus trading along the river. The home's massive walls consist of two layers of limestone interfilled with rubble and are nearly 2 feet thick, sitting on bedrock. The walls being intermittently loopholed to allow muskets to be fired from within the house. A natural spring within the cellar provides its the occupants with water without exposure to outside elements.

    By 1775 a line of settlements stretched westward along the Mohawk Valley, 65 miles west of Schenectady to German Flats. Agriculturally rich, the valley served as a major breadbasket for the patriot cause. It's white population of about 15,000 settlers provided a militia force of about 2,500 men. As the danger of invasion from Canada increased, settlers in the valley began erecting a series of military posts along with enclosing several stone houses and churches with log stockages. This provided a total of 24 strong posts to guard the valley. The primary purpose of the fortified homes were to provide places of safety where neighbors could seek refuge when bands of raiding Indians and Tories swept through the valley.

    On October 19th, 1780, marauders under the command of Sir John Johnson passed near the home. It was while this force was passing that John Leonard Crouse, a son-in-law of Johannes Klock, fired upon the enemy and killed a British horseman whose gear he later recovered. Before the close of that day, Sir John's force were surrounded by Rebel forces under the command of Brigadier General Robert Van Rensselaer, just a short mile west of the fort, and forced to make a dangerous night crossing of the Mohawk River with the loss of most of their equipage and plunder.

    By 1781, after six years of constant warfare, conditions in the Mohawk Valley were severe. More than 700 homes and barns in area streching from Tribes Hill in the east, to Vrooman's Land at the headwaters of the Schoharie Creek in the southeast, to Cherry Valley in the south and to Springfield in the southwest, to Mayfield in the north, & to Forts Herkimer and Dayton in the west had been burned, the white population had been reduced to less tha 2,000 and its effective militia to less than 800 men. Ten thousand people had been forced to flee the Upper Mohawk Valley or risk being killed or taken prisoner. It was the privately fortified structures such as Fort Klock that enabled the 2,000 or so remaining settlers to continue living in the Mohawk Valley until the end of hostilities in the summer of 1782.