In the 1640s, when John Griffin and Michael Humphrey first crossed the Farmington River at "The Falls", they were searching for virgin pine forest where they could pursue their tar and pitch business. What they found was a verdant valley bounded by two low mountain ranges, rich with fish and wildlife. The native Massacoe Indians,of the Algonquin Nation, had lived off the bounty of the rich land and flowing river. The new settlers called the valley the "Massacoh Plantation."
Between 1648 and 1661, Indian lands were gradually deeded over to the Englishmen. In 1670, the Massacoh Plantation came to be named "Simsbury", probably after Symondsbury, Dorset, England. Many of the earliest English settlers came from Dorset, including Thomas Ford, the first to clear land and farm here.
In 1676, Indian disputes erupted into King Philip's War, and in March Simsbury was attacked by a group of Philip's warriors and burned to the ground. According to legend, their leader, King Philip, sat in the large cave on Talcott Mountain to view the spectacle. It is still called the Metacomet Ridge.
The War of the Revolution had a profound effect on the Town. Nearly 1,000 Simsbury residents, more than in any other war, served in the Revolution. One hundred Simsbury soldiers engaged in the Battle of Bunker Hill. Noah Phelps was the most noted hero, as it was his spying which led to the capture of Fort Ticonderoga by Ethan Allen and his Green Mountain Boys.
In 1705, copper was discovered in Simsbury. Later, the copper mine becamethe infamous New-Gate Prison of the Revolutionary War. The first copper coinage in America was started by Doctor Samuel Higley of Simsbury in 1737.
In 1728, the first steel mill operating in America was located in Simsbury.