and also served as field transportation inspector in the Trans-Mississippi Department. His wife and children remained at Chatham until the spring of 1862 when Union troops' arrival forced them to abandon the building and move in with relatives across the river in soon-beleaguered Fredericksburg, and after its fall later to Pulaski County. For much of the next thirteen months, Chatham was occupied by the Union army; orders, reports, and letters referred to it as the "Lacy House". Northern officers initially used the mansion as a headquarters. In April 1862, General Irvin McDowell brought 30,000 men to Fredericksburg and supervised the repair of the Richmond, Fredericksburg and Potomac Railroad and construction of several bridges across the Rappahannock River from Chatham. McDowell planned to use the new bridges to march south and join forces with the Army of the Potomac outside Richmond. President Abraham Lincoln journeyed to Fredericksburg to confer with McDowell about the movement, meeting with the general and his staff at Chatham. His visit gave Chatham the distinction of being one of three houses visited by both Lincoln and Washington (the other two are Mount Vernon and Berkeley Plantation on the James River east of Richmond.) While at Chatham, Lincoln went to Fredericksburg, walked its streets, and visited a New York regiment encamped on what would become known as "Marye's Heights" during a later battle. Seven months after Lincoln's visit, fighting again erupted at Fredericksburg. In November 1862, General Ambrose E. Burnside brought the 120,000-man Army of the Potomac to Fredericksburg. Using pontoon bridges, Burnside crossed the Rappahannock River below Chatham, seized Fredericksburg, and launched a series of bloody assaults against Lee's Confederates, who held the high ground behind the town. One of Burnside's top generals, Edwin Sumner, observed the battle from Chatham while U.S. artillery batteries shelled the Confederates from adjacent bluffs. Furthermore, a German Military Observer, Count Zeppelin, from Chatham's lawn, sent up a reconnaissance balloon with a soldier to observe the battle, an incidence he later often recounted after starting his aircraft factory. The Battle of Fredericksburg became a disastrous Union defeat. Burnside suffered 12,600 casualties, many of whom were brought back to Chatham and the nearby Conway House (Falmouth, Virginia) for care. For several days, army surgeons operated on hundreds of soldiers inside the house. Assisting them were volunteers, including the poet Walt Whitman, Clara Barton (who later founded the American chapter of the International Red