(September 17, 1862.)
Horse Batteries C and G (consolidated), 3d U.S. Artillery, crossed the Antietam in the forenoon of September 17, and went into position a short distance south of this point, on the left of Battery M, 2d U.S. Artillery, and the right of Batteries B and L (consolidated), 2d U.S. Artillery. After an engagement of nearly two hours it was relieved by Battery E, 1st U.S. Artillery, and withdrawn east of the Antietam, taking up its second position on the ridge north of the Boonsboro Pike.