In 1992, lifelong Portsmouth residents Dr. Louis R. and Ava Chaboudy conceived the idea of painting murals on the floodwall after seeing outdoor murals in Steubenville, Ohio, and an ad hoc committee decided to turn the floodwall into an outdoor art gallery portraying the history of Portsmouth and the surrounding area. In May 1993, muralist Robert Dafford of Lafayette, Louisiana, began work on the project’s longest mural, a 1903 scene of Portsmouth, and by October 2002 the project was completed with 2,200 square feet of art and 52 murals. Among its historical subjects are the Mound Builders, who built and occupied mounds in Southern Ohio long before explorers came to the New World, including horseshoe-shaped mounds in Mound Park aligned southeastward across the Ohio River toward a medicine wheel mound at the Hardin Farm near Siloam, Kentucky, a lineup said to have held equinoctial significance. Other subjects include a Shawnee village in 1730, reflecting a people who first arrived in the Mid Ohio Valley during the 1100s from Central Mexico and returned in the late 1600s from Pennsylvania, and Celeron de Blainville’s 1749 meeting at the confluence of the Ohio and Scioto Rivers with Native Americans and a few British traders as he laid claim to the Ohio Valley and its tributaries by burying lead plates along the Ohio River.