Born: 1786-06-30 Amherst, Massachusetts
Died: 1877-01-02 Springfield, Illinois
Thayer moved to Springfield, Illinois, in 1834. In May 1835, he opened a dry goods store. He entered into partnership with Ezra Lyman, John Lyman, and Luther N. Ransom. The firm of Thayer, Lyman, and Ransom continued until February 1837, when the partners dissolved the enterprise by mutual consent. Thayer continued in business with Ransom as the firm Thayer, Ransom & Co. In February 1838, Thayer entered into partnership with his son, Edward R. Thayer, to form Joseph Thayer & Co., and in March, Thayer bought out Ransom and dissolved Thayer, Ransom & Co. In 1860, he had real estate and financial holdings valued at $50,000.
In addition to his commercial ventures, Thayer was active in religious and civic causes. He was an active member of the Second Presbyterian Church of Springfield, serving as an elder. In 1835, members of the Sangamon Bible Society elected him as a director, and in 1836, he won election as treasurer. In January 1845, he became manager of the newly-formed Illinois State Colonization Society. In June 1847, he was a vice-president of the Sabbatarian Convention held in Springfield.
Thayer married twice. His first wife, Susannah (Susan) Thayer died in December 1836, and in 1838, he wed a second time, marrying Anna S. Canfield.
John Carroll Power and S. A. Power, History of the Early Settlers of Sangamon County, Illinois (Springfield, IL: Edwin A. Wilson, 1876), 710; Sangamo Journal 6 June 1835, 3:5; 28 November 1835, 3:2; 24 December 1836, 2:5, 3:3; 1 April 1837, 3:3; 10 February 1838, 3:1; 24 March 1838, 2:7; 23 January 1845, 3:4; 15 July 1847, 3:5; Illinois Statewide Marriage Index, Sangamon County, 11 January 1838, Illinois State Archives, Springfield, IL; U.S. Census Office, Eighth Census of the United States (1860), Sangamon County, IL, 242; Gravestone, Oak Ridge Cemetery, Block 14, 15, Springfield, IL; Obituary, Daily Illinois State Register 3 January 1877, 1:4, 4:1.