The enemy receiving large reinforcements, was enabled to mass about two thousand men at San Jorge, where they were a constant danger and annoyance. Walker determined to dislodge them. On the 16th of March he took personal command of four hundred men, and marched out to meet the enemy, two thousand five hundred strong. Henningsen, with two six-pounders, one twelve-pounder, and four mortars, went ahead to clear the way. Swingle and the rest of the battery remained to guard Rivas; and it was well that they did so, for a large force of Costa Ricans made a determined assault as soon as Walker was out of sight, and were not repulsed until after a fight of some hours' duration. They fell back on the road to San Jorge, a couple of hundred of them taking up a position behind the adobe walls of a planter's house, and there lying in wait for the return of Walker and his command.
The latter arrived before daybreak at the suburbs of San Jorge and at once opened a brisk fire on the town; but the enemy were on the alert, and swarmed like angry bees out of their streets and lanes, pressing on the battery and throwing out lines of skirmishers on either side, who opened a galling fire on the American cavalry. Henningsen thereupon threw a shower of grape and canister among the plantain fields on the right and left, driving in the skirmishers, while Walker led the main body of his men towards the centre of the town. The enemy contested every inch of the ground, until driven to within three hundred yards of the plaza, where their immense superiority of numbers and the shelter afforded by the adobe walls and church towers gave them a position of impregnable strength. Walker, nevertheless, called for forty volunteers to storm the place. But fifteen responded, and with that handful he charged boldly into the plaza, fighting with desperate but vain courage against the tremendous odds. Two horses were killed under him, and a spent ball struck him in the throat. His men were brave to madness, but they were worn out with the long day's service, their ammunition was running short, and Walker at last gave order to retire to Rivas. They left the field on which they had fought from daybreak almost to sunset in good order, Walker riding at the head of the column, and Henningsen covering the rear with his guns. No opposition was made to their departure, and not until the head of the column came abreast of the planter's house at Cuatros Esquinas did they learn of the presence there of the 200 Costa Ricans who had been repulsed by Swingle in the morning.