Cavalry Regiment commanded by Lt. Col. David R. Clendenin. Wallace moved in additional troops to assist them, including the 11th Maryland, a field artillery unit, and Ohio units from Annapolis and Baltimore. Wallace's men skirmished with Early's cavalry west of Frederick on July 7, but later retreated toward Monocacy Junction to avoid being surrounded. Following the skirmishing on July 7 and 8, when Confederate cavalry drove Union units from Frederick, Early demanded, and received, $200,000 ransom from the city to save it from destruction. Wallace's prospects improved when word arrived that the first contingent of VI Corps troops, commanded by Ricketts, had reached Baltimore. Although they were originally ordered to travel by rail to Harpers Ferry, Ricketts and about 3,300 of his men arrived at Monocacy Junction, where Wallace stopped them on the evening of July 8. Ricketts agreed to remain at the Monocacy to assist Wallace. When Wallace informed Halleck that the Confederates were threatening the road to Washington, Halleck wired Grant to send reinforcements to the capital. The Union troops at Monocacy Junction would have to delay Early's troops, who were within a two-days' march of Washington. On Saturday, July 9, the combined forces of Wallace and Ricketts, about 6,800 men, were positioned at the bridges and fords of the river. The higher elevation of the river's east bank formed a natural breastwork for some of the men, while Tyler's brigade occupied the two block-houses and trenches his soldiers had dug near the bridges. Ricketts's division occupied the Thomas and Worthington farms on the Union left, using the fences as breastworks. Confederate troop estimates ranged from 14,000 to 28,000 men, nearly double the size of the Union forces. Opposing forces Union Confederate Battle Wallace’s objectives for the battle were simple: keep the road to Washington secure as long as possible and maintain a line of retreat for his men. On July 9, between 9 and 10 a.m., Confederate Maj. Gen. Stephen Dodson Ramseur's division encountered about 3,500 of Rickett's men along the bluffs overlooking the bridge where the Georgetown Pike crossed the river, while Maj. Gen. Robert E. Rodes's division clashed with Tyler's brigade, who were guarding the Baltimore Pike and its stone bridge across the river. Clendenin's Union cavalry was downstream, watching the river. Prisoners taken during this phase told the Confederates that the entire VI Corps was present, which seemed to have heightened the Confederates' caution