On the morning of July 19, 1863, Confederate Brigadier General John Hunt Morgan learned that the Union redoubt guarding the ford had been abandoned during the night, and he ordered Colonel Basil Duke to send a force south to try to preserve the element of surprise while Morgan and most of his troops prepared to cross the river. At the same time, a Union force under Brigadier General Henry Judah had landed from riverboats at Portsmouth and was marching east through Pomeroy and Racine. Thick fog in the valley brought the opposing forces to within 50 yards of each other before either realized it, and when a breeze cleared the air the Confederates fired a devastating opening volley that forced the Union troops to retreat and mortally wounded Major Danie McCook, patriarch of the Fighting McCooks. The Battle of Buffington Island began at 5:30 am when Judah's advance guard collided with Duke's 5th and 6th Kentucky Cavalry near the Williamson house, and after Duke's men broke the Union line, captured an artillery piece, and advanced to the first bend in the road, a counterattack slowly pushed them back toward Portland. After heavy fighting, Duke's artillery was captured on a low knoll around 6:15 am, General Hobson's Union cavalry attacked Colonel Johnson's Confederates along modern County Road 31, and Lieutenant Commander Fitch's gunboat USS Moose bombarded Confederate positions, leaving Morgan's cavalrymen facing threats on three sides. Duke made several unsuccessful attempts to retake the guns, but because his position had become untenable he began to withdraw north, while the Williamson House served as a temporary field hospital for both Union and Confederate soldiers.