The principal architect behind the design of the U.S. Capitol was William Thornton, who won the design competition in 1792. His neoclassical design was selected for its grandeur and vision, symbolizing democracy and the new American republic. Thornton's initial plans were later modified by other architects, especially Benjamin Henry Latrobe and Thomas U. Walter, who contributed to the Capitol's iconic dome and extensions. The building's architecture reflects the influence of classical ancient structures, aiming to evoke stability and permanence, aligning with the democratic ideals it represents. Today, the U.S. Capitol stands as a significant landmark in American governance.