Little Haddam served as the town center .
Little Haddam was later supplanted by locations on the river , where early economic activity was significant , and by Moodus , which developed as an industrial and economic center in the 19th century .
Little Haddam served as the town center , but was later supplanted by locations on the river , where early economic activity was significant , and by Moodus , which developed as an industrial and economic center in the 19th century .