East Haddam is a town in Middlesex County, Connecticut, United States. The population was 9,126 at the 2010 census.
Until 1650, the area of East Haddam was inhabited by at least three tribes of Indians: the Wangunks, the Mohegans and the Nehantics. The Indians called the area "Machimoodus", the place of noises, because of numerous earthquakes that were recorded between 1638 and 1899. Loud rumblings, the "Moodus Noises", could be heard for miles surrounding the epicenter of the quakes near Mt. Tom. The land, which is now Haddam and East Haddam, was purchased by settlers from the natives in 1662 for thirty coats – worth about $100.
Layout of the highways began in 1669 with Creek Row about ¼ mile east of the River and Town Street “The Great Highway” about ¼ mile east of Creek Row. The first permanent settlers established homesteads along Creek Row in 1685. By 1700, there were thirty families living in East Haddam. Agricultural and timber farming, shipbuilding, tanneries and blacksmiths were among the early commerce.