The region was first settled by Europeans in 1765 by William Gilliland. Originally called "Milltown" by its founder (for the saw mill he located on the falls of the Boquet River, located in the center of the town), it was renamed "Willsborough" (subsequently shortened to "Willsboro") shortly after the Revolutionary War, in honor of the founder.

 

The town has always had a thriving agricultural and tourism tradition, though the Industrial Revolution made its mark in the community as well. Through much of its history, Willsboro's main employer was a paper mill (which produced the wood pulp used in the making of paper). A blue Limestone quarry was also an important industry locally. The stone quarried from this mine was utilized in the construction of the Albany State Capitol and the Brooklyn Bridge.

 

One of the noted residents was the paper manufacturer Augustus G. Paine, Jr., who resided in Willsboro for a portion of the year, when he was not in New York, since his large business was located there. He commissioned the architect C. P. H. Gilbert to construct the Essex County Bank in 1921. In May, 1930, Paine also donated a whole library to the town of Willsboro, in memory of his mother, in the sum of $150,000. Both the bank and the library were constructed by Gilbert in the Neoclassical style.

 

After the Second World War the paper industry started to decline, and when the paper mill closed in the 1960s the town faced hard economic times. In order to make up for the loss, the community relied heavily on tourist dollars, focusing on the scenic landscape, lake frontage, and lush wilderness the area offered visitors. Recently, new industries have moved to the town, most notably a wollastonite mine, curtain and furniture manufacturers, and numerous web-based service companies.