The town was originally granted in 1760 as part of the New Hampshire Grants and named Bessborough. It was regranted by Vermont in 1786 as Dunmore, and settled the same year.
An early settler was Dr. Jonathan Arnold, a member of the Continental Congress and author of Rhode Island's act of secession from the United Kingdom in May of 1776. Arnold left Rhode Island in 1787 and, with six other families, built homes at what is now the town center.
By 1790, the village had grown to 143 inhabitants, and the first town meeting took place in Arnold's home that year, where the name St. Johnsbury was adopted. According to local lore, Vermont founder Ethan Allen himself proposed naming the town St. John in honor of his friend Jean de Crèvecœur, a French-born author and agriculturist and a friend of Benjamin Franklin (he was known in the United States as J. Hector St. John). According to this account, de Crèvecœur suggested instead the unusual St. Johnsbury to differentiate it from Saint John, New Brunswick.
In the mid-19th century, St. Johnsbury became a minor manufacturing center, with the main products being scales — the platform scale was invented by Thaddeus Fairbanks in 1830 — and maple syrup and related products. With the coming of the railroad line from Boston to Montreal in the 1850s, St. Johnsbury grew quickly and was named the shire town (county seat) in 1856, replacing Danville. The oldest occupied residence in St. Johnsbury was built in 1801 and is located on Clarks Avenue.
The former St. Johnsbury Fairgrounds were located where Interstates 91 and 93 converge, south of the town. The Third Vermont Regiment drilled there prior to joining the Union Army during the Civil War.
The first air flight in Vermont occurred at the fair September 24, 1910.
In the 1940s the city contained three major industries. Each was the largest in the world. One was Fairbanks Scales, another was a maple sugar candy company, a third made those old candlestick bowling pins. The rest of the economy was mostly rural.
Information from Wikipedia, the free encyclopedia VIA: http://en.wikipedia.org/wiki/St._Johnsbury,_Vermont