Blennerhassett Island, located just downriver from Parkersburg, is named for Harman Blennerhassett, an Irish aristocrat who brought his young wife, Margaret, to the island in 1798 and built a paradise there with a gleaming white mansion as its centerpiece. The large circular home, completed in 1800 at a cost of $40,000, sat at the upper end of the island, where people traveling down the Ohio River could see its magnificence. But Blennerhassett's cultured and intellectual background hadn't prepared him for life on the frontier. Generous, extravagant and often impractical, he squandered much of his fortune. Growing desperate, Blennerhassett fell under the spell of Aaron Burr, a former Vice President under Thomas Jefferson who, in 1806, was planning to raise an army against Spanish troops in New Orleans and estabish his own Southwest government. Using Blennerhassett's island as a headquarters, recruitment center and training area, Burr put together a small expedition of boats and soldiers. However, as soon as President Jefferson got word about Burr's plot, he gave the Ohio governor power to use the local militia to break up the "hostile activities." Blennerhassett fled his island paradise, was arrested for treason and lost the last of his money defending himself in court in Richmond, Virginia. Financially broken, he took his wife and children back to England, where he died in 1831, age 66. His wife died eleven years later in New York City.

The Blennerhassett mansion burned down in 1811 and the annual floodings of the island covered over its foundation stones. In 1973 West Virginia state archeologists rediscovered the foundations, which were then used as a template for a beautiful and historically accurate replicate mansion built there in the 1980s. The island is now a West Virginia State Park.