Harman Blennerhassett was involved in Aaron Burr's conspiracy against the United States of America in the early 1800s.
Although Blennerhassett was born circa 1767 in Hampshire, England, his family was from Ireland. He graduated from Trinity College and then became a lawyer. Blennerhassett's father died in 1796, leaving his son a fortune in excess of 100,000 dollars, including an estate in Ireland. Blennerhassett married the daughter of the governor of the Island of Man. She was also Blennerhassett's niece, and the couple moved to the United States in 1797. Some scholars believe that the Blennerhassetts left Ireland to leave knowledge of the scandalous marriage behind them. That winter, the Blennerhassetts moved to Marietta, Ohio, where they purchased 174 acres of land on an island, now known as Blennerhassett Island, in the Ohio River. The land formerly belonged to George Washington.
For the first several years that the Blennerhassetts lived on the island, they resided in a blockhouse. In 1800, they moved into a mansion. In their new home, the couple lived the life of the wealthy. Harman conducted scientific experiments, formed an extensive private library, and paid detailed attention to his agricultural fields. Numerous prominent people visited the Blennerhassett home. Perhaps their most famous guest was Aaron Burr, a former Vice President of the United States.
Burr first visited the Blennerhassetts in 1805. He had been planning to lead a rebellion against the United States. He hoped to break away the western part of the United States to form a new country that he would lead. Burr convinced Harman Blennerhassett to participate in his rebellion.
In September 1806, Blennerhassett ordered the construction of fifteen boats. Burr and Blennerhassett would use the vessels to transport up to five hundred followers to the site of their new empire. Blennerhassett spent his entire fortune paying for the planned expedition. Besides his holdings along the Ohio River, Blennerhassett also owned land and slaves in the Deep South.
The United States government heard rumors of the uprising. Governor Edward Tiffin of Ohio dispatched the state's militia to the convergence of the Muskingum and Ohio Rivers. The militia was to stop all river traffic traveling down the two rivers. The United States government also sent a detachment of Virginia militia to seize the Blennerhassetts' island. Harman Blennerhassett was in hiding. His wife was away in Marietta. When she returned, she discovered that the militiamen had ransacked the home. She fled with her three children. Her husband was arrested a few weeks later, but he quickly gained his release. The Blennerhassetts briefly returned to their mansion, but now destitute from Harman's support of Burr, they sought their fortunes in Mississippi. The mansion burned in 1811. In Mississippi, the family bought a cotton plantation, but the Blennerhassetts were forced to sell it roughly a decade later.
The family remained in poverty for the duration of Harman's life. He died in 1831. Mrs. Blennerhassett died in 1842 in a home for the poor in New York. The Blennerhassetts' three sons also experienced difficult lives. One son simply disappeared after a night of drinking; another son starved to death in the attic of a building in New York; and the final son died while serving in the Confederate military during the Civil War.
- Fess, Simeon D., ed. Ohio: A Four-Volume Reference Library on the History of a Great State. Chicago, IL: Lewis Publishing Company, 1937
- Fitch, Raymond E. Breaking with Burr: Harman Blennerhassett's Journal, 1807. Athens: Ohio University Press, 1988.
- Swick, Ronald Ray. "Harman Blennerhassett: An Irish Aristocrat on the American Frontier." Ph.D. diss., Miami University, 1978.