Elizabeth Cornwall (maiden name: Whitmore) was born on October 9, 1821, in Chatham (present-day East Hampton), Connecticut, to Dennis Whitmore and Sophronia Strong. She married Andrew Cornwall on January 20, 1843, and they had at least three children: Henry, born on November 16, 1843; Dwight, born on July 14, 1851; and Demas, born on April 15, 1855. The family lived in Portland, Connecticut, and her husband worked as a farmer.
By 1860, they owned $6,000 of real estate and $2,000 of personal property. A decade later, they owned $7,000 of real estate and $4,500 of personal property. Her husband died on July 7, 1894. She remained in Portland, and by 1900, she was living with her son Dwight. She lost her hearing late in life, but she reportedly “retained her mental vigor until the last.” According to a local writer, she “lived a retired life for several years,” but she was “hospitable and always thoughtful of others.” She died on April 10, 1907.