Elihu Dwight was born on October 22, 1763 in Belchertown, Massachusetts to Justus Dwight and Sarah Lamb Dwight. After graduating from Dartmouth College in 1790, he studied medicine with Dr. Ebenezer Hunt in Northampton, Massachusetts. Dwight became one of the first physicians to establish a medical practice in South Hadley, Massachusetts. On October 7, 1801, he married Lydia White of Springfield, Massachusetts. They had four daughters and four sons together. He became a successful businessperson and acquired a good deal of property in the local area. He also made a substantial donation towards the establishment of the Mount Holyoke Female Seminary. At ninety, he died in his South Hadley home on June 1, 1854.