McGregor's Battery [also known as the Stuart Horse Artillery 2nd Battery] was organized in August 1862, by dividing Pelham's original company. This unit was assigned to J. Pelham's, R. F. Beckham's, J. Breathed's and R. P. Chew's Battalion of Artillery, Army of Northern Virginia. It was involved in many conflicts from Fredericksburg to Cold Harbor, then participated in the defense of Petersburg and the Appomattox operations. The battery reported 6 casualties at Fredericksburg and 20 at Chancellorsville, had 106 engaged at Gettysburg, and surrendered only 2 in April 1865. Its commanders were Captains G. Wilmer Brown, M. W. Henry, and William M. McGregor.