When Hooker moved to the right at Bolivar by way of the Hagerstown road, Gibbon continued on the main road and attacked Colquitt, in position about 700 yards southeast of this point. He drove Colquitt's skirmishers and reached the bend in the road in Colquitt's front, but was unable to drive Colquitt, and bivouacked in his front. When darkness put an end to the engagement, Cox's Division of the Ninth Corps held the summit of the mountain, south of Fox's Gap. Hooker's First Corps gained the high ground northeast, commanding the Confederate line of retreat on Boonsboro, and Gibbon held the ground gained by him along the turnpike to the south. The Confederate line of retreat being in great jeopardy, Lee, immediately after dark put his Army in motion for Sharpsburg, where Jackson, Walker and McLaws joined him.