Ancram is in the southeast corner of the county.
Recorded as part of the land grant to the Livingston family, this area on the Roeliff Jansen Kill was originally called "Livingston Forge" after the iron foundry developed on the river. Throughout the eighteenth century, the Livingston forge created metal products for the community. The town was sometimes known as "Scotchtown" due to the immigrants of Scottish ancestry who flocked there in the late 18th century. As the Revolution drew near, the factory produced shot, cannonballs, and perhaps most importantly, the huge chain which was installed across the Hudson River at West Point as a defense against British ships going upriver.
After the Revolution, the town was established from part of the town of Livingston in 1803, and was then called "Gallatin". In 1814, the name was changed to "Ancram", after the town in Scotland where the Livingstons had their origins. Part of Ancram was taken to form a new town of Gallatin in 1830.
The hamlet of Boston Corner was formerly part of the town of Mount Washington, Massachusetts. Because it was more accessible from Ancram, it was annexed by the New York town on April 13, 1857, by an agreement between the states.