The approach to the capital was difficult. It was by two roads, each along a stone aqueduct. On the Belen road the Mexicans were gradually pressed back, however, and the Americans entered the first work, where they were confronted by the citadel commanded by Santa Anna. A terrible fire rendered further advance impossible. On the San Cosme road the enemy was pursued to a second barricade, which was carried under Lieutenant U.S. Grant and Lieutenant Gire. Worth's columns pushed on. Having passed the arches, they began breaking their way through the walls of the houses. Howitzers were hauled to the roofs, and at last the main gate was carried. During the night a delegation proposed a capitulation. Scott refused to grant terms. At dawn Quitman advanced to the grand palace and occupied the Plaza, and an hour later Scott took up his headquarters there. Presently some 2,000 liberated convicts and others began casting paving stones on the soldiers, and it became necessary to sweep the streets with grape and canister. By the 15th Scott was in full possession of the City of Mexico. [Sidenote: Flight of Santa Anna] On the morning of September 14, Generals Quitman and Worth raised the American flag over the national palace, and Scott soon afterward reined up at the Grand Plaza, where he removed his hat, and, raising his hand, proclaimed the conquest of Mexico. Santa Anna's men afterward treacherously attacked the hospital at Puebla, where were 2,000 Americans, sick and wounded. They bravely resisted and were presently rescued; the Mexicans being routed by General Lane. Santa Anna, again a fugitive, fled for safety to the shores of the Gulf. [Sidenote: Many reputations made] Among the officers who distinguished themselves were many who gained a lasting reputation fifteen years later, during the American civil war; for instance, Jefferson Davis, Grant, Lee, McClellan, Beauregard, Sherman, Hill, Jackson, Hooker, Longstreet, Buell, Johnston, Lyon, Kearney, Reynolds, French, Ewell and Sumner. [Sidenote: Premonitions of trouble in France]