Scott, to say that he would begin
the attack at daybreak next morning.

It rained all night and the men lay in the mud without fires. At three
in the morning (August 20th) the word was passed to march. Such pitchy
darkness covered the face of the plain that Smith ordered every man to
touch his front file as he marched. Now and then a flash of lightning
lighted the narrow ravine; occasionally a straggling moonbeam pierced
the clouds and shed an uncertain glimmer on the heights; but these
flitting guides served only to make the darkness seem darker. The
soldiers groped their way, stumbling over stones and brushwood, and did
not gain the rear of the camp till day broke. Then Riley bade his men
look to the priming of their guns, and reload those which the rain had
wet. With the first ray of daylight the firing had begun again between
the Mexican camp and Ransom's corps stationed in front and Shields's
brigade at San Jeronimo. Almost at the same moment Riley began to ascend
the height in the rear. Before he reached the crest, his engineers, who
had gone forward to reconnoitre, came running back to say that his
advance had been detected, that two guns were being pointed against him,
and a body of infantry were sallying from the camp, The news braced the
men's nerves. They gained the ridge, and stood a tremendous volley from
the Mexicans without flinching. Hanson of the Seventh--a gallant officer
and an excellent man--was shot down with many others; but the Mexicans
had done their worst.

With steady aim the volley was returned; and ere the smoke rose a cheer
rang through the ravine, and Riley fell with a swoop on the
intrenchments. With bayonet and butt of musket, the Second and Seventh
drove the enemy from his guns, leaping into his camp and slaughtering
all before them. Up rushed Smith's own brigade on the left, driving a
party of Mexicans before them, and charging with the bayonet straight at
Torrejon's cavalry, which was drawn up in order of battle. Defeat was
marked on their faces. Valencia was nowhere to be found. Salas strove
vainly to rouse his men to defend themselves with energy; Torrejon's
horse, smitten with panic, broke and fled at the advance of our
infantry. Riley hurled the Mexicans from their camp after a struggle of
a quarter of an hour; and as they rushed down the ravine, their own
cavalry rode over them, trampling down more men than the bayonet and
ball had laid low. On the right, as they fled, Cadwallad