the completion of both wings, the Capitol was partially burned by the British on August 24, 1814, during the War of 1812. George Bomford and Joseph Gardner Swift, both military engineers, were called upon to help rebuild the Capitol. Reconstruction began in 1815 and included redesigned chambers for both Senate and House wings (now sides), which were completed by 1819. During the reconstruction, Congress met in the Old Brick Capitol, a temporary structure financed by local investors. Construction continued through to 1826, with the addition of the center section with front steps and columned portico and an interior Rotunda rising above the first low dome of the Capitol. Latrobe is principally connected with the original construction and many innovative interior features; his successor Bulfinch also played a major role, such as design of the first low dome covered in copper. The House and Senate Wings By 1850, it became clear that the Capitol could not accommodate the growing number of legislators arriving from newly admitted states. A new design competition was held, and President Millard Fillmore appointed Philadelphia architect Thomas U. Walter to carry out the expansion. Two new wings were added: a new chamber for the House of Representatives on the south side, and a new chamber for the Senate on the north. When the Capitol was expanded in the 1850s, most of the construction labor was carried out by slaves "who cut the logs, laid the stones and baked the bricks". The original plan was to use workers brought in from Europe. However, there was a poor response to recruitment efforts; African Americans, some free and some enslaved, along with Scottish stonemasons, comprised most of the workforce. Capitol dome The 1850 expansion more than doubled the length of the United States Capitol; it dwarfed the original, timber-framed, copper-sheeted, low dome of 1818, designed by Charles Bulfinch which was no longer in proportion with the increased size of the building. In 1855, the decision was made to tear it down and replace it with the "wedding-cake style" cast-iron dome that stands today. Also designed by Thomas U. Walter, the new dome would stand three times the height of the original dome and in diameter, yet had to be supported on the existing masonry piers. Like Mansart's dome at Les Invalides in Paris (which he had visited in 1838), Walter's dome is double, with a large oculus in the inner