In January 1862, Cothran’s battery was given six ten-pound Parrott rifles together with teams of horses. The unit was assigned to the command of Major General Nathaniel Banks in the Department of the Rappahannock. It was positioned at Frederick, Maryland and nearby Point of Rocks. The battery finally saw active service in March, when Banks took his forces into Virginia. The battery saw action at the First Battle of Winchester on May 25, 1862. Winegar, who was ill at the time, still took command of a section of the battery. He was mentioned in dispatches for creditable behavior during Banks’ retreat after the battle. (Cothran had been arrested on a charge of defrauding the government and faced a court martial. He was convicted but was reinstated on June 4.) Battery M also served at the Battle of Cedar Mountain, serving on the far right of Banks' line.