East Haddam is located in Middlesex County northwest of New London between Portland and Essex along Highway 154 on the banks of the Connecticut River near Long Island Sound. Brainerd Homestead State Park is just north.
The land was part of an original purchase from the Indians in 1662 for thirty coats - about $100. It included Machimoodus, "the place of noises." So named from subterranean sounds formerly heard there. The First Ecclesiastical Society was formed in 1704.