outflanked]

In America, after several months of comparative inaction, the war in Mexico
was renewed with vigor. On August 6, General Scott received reinforcements.
Leaving a governor at Puebla, he marched on with 14,000 men. He met with no
resistance at the passes of the Cordilleras. On August 10, from the top of
the Rio Frio Mountains, the City of Mexico, lying in a fertile, lake-dotted
basin, was in sight. The land around the city was under water, and the
capital was approached by causeways across the low and marshy ground. The
numerous rocky hills were all fortified. Scott passed around Lake Chalco to
the southwest, and thence moved west skirting the south shore. Santa Anna,
intercepting the Americans, took up his headquarters at San Antonio, five
miles from the city. His position was flanked on the west by broken lava,
and on the east by marshy ground. The ground was as bad as could well be
encountered. Santa Anna sent orders to General Valencia, who held a
fortified hill in front of the Americans, to spike his guns, destroy his
stores and retreat, but Valencia refused. Riley, occupying a hill in his
rear, took his intrenchments in reverse. He was cut off both north and
south; 2,000 of his force were killed and wounded; a thousand with four
generals were captured, and guns, stores and ammunition fell into the hands
of the Americans.

[Sidenote: Battle of Contreras]

The divisions of Pellow and Twiggs were ordered, August 19, to storm
Contreras. The line between that position and Santa Anne's reserves was cut
at the close of the day, and General Persifer F. Smith at sunrise the next
morning led an assault on the Mexican camp, and in less than half an hour
drove 6,000 Mexicans out of the fortification. Shortly afterward General
Worth attacked Santa Anna and routed the garrison.

[Sidenote: Churubusco]

The Americans followed to Churubusco on the road to the capital, where
Santa Anna had concentrated his whole force. Here the river was protected
by levees, the head of the bridge strongly fortified, and the stone convent
surrounded by a strong field-work. The attack on the bridge and the
convent was desperate. Pierce and Shields had made a detour to the main
road in the rear of Churubusco. They struck the Mexican reserves, and all
the troops on both sides were engaged. Worth and Pellow carried the bridge
in time to save Pierce and Shields. The Mexican left gave way. A detachment
crossed the river and threatened th