Between June 12 and June 28, 1862, during the Peninsula Campaign, Union Gen. George B. McClellan maintained his headquarters at the Trent House, also known as Reynoldsville, a house built about 1825 and occupied during the war by Dr. Peterfield Trent, a surgeon in a local Confederate defense regiment. After Union forces under McClellan advanced west from Fort Monroe up the Peninsula toward Richmond and overcame three Confederate defensive lines, the house and surrounding fields became the nerve center of the Army of the Potomac as McClellan and his staff planned the final phases of the campaign. Telegraph wires spread in all directions, a signal station stood nearby, and aeronaut Thaddeus S. C. Lowe periodically ascended in an observation balloon from a nearby ridge. From here McClellan monitored the Battle of Gaines' Mill on June 27, and that night, after realizing his plan to capture Richmond had failed, he called a council of war with his corps commanders and announced that the army would abandon its lines before the city and withdraw south to a new base on the James River. The headquarters moved to Savage's Station the next morning and then to the James River, leaving burned supplies behind.