In 1814, during the War of 1812, the mansion was set on fire by the British Army in the Burning of Washington. Some of the soldiers who burned it were former slaves who had run away from their owners to fight with the British. They ate dinner in the house before setting it on fire. The fire destroyed the inside of the house and charred much of the outside. Reconstruction began almost immediately. President James Monroe moved into the partially reconstructed house in October 1817. Construction continued with the addition of the South Portico in 1824 and the North in 1829. 