Up to this time the guerrillas had been engaged in but few skirmishes, their services consisting chiefly in small foraging expeditions, making themselves thoroughly acquainted with the topography of the country preparatory to engaging in more effective measures. There was a slight brush at Richfield, in which Captain Scott, with twelve of Quantrell's men, surprised thirty militia whom they captured, after killing ten, and in this attack Jesse James participated. Upon his return to camp he was sent out with orders from Quantrell to scour the counties adjoining Clay and locate the militia. After passing through Clinton county he paid a short visit to his mother, who received him with many manifestations of pleasure, and then began to unload herself of the valuable information she had gathered for the benefit of the guerrillas. She told him that the attack on Richfield had resulted in massing the militia for a determined stroke, and that the troops were concentrating near that point; that Plattsburg had been almost entirely relieved of its garrison and would fall an easy prey to the guerrillas if they chose to profit by the opportunity.

Jesse lost no time in communicating the situation to Quantrell, and, accordingly, three days after the capture of the squad of militiamen at Richfield, Captain Scott took fifteen men and silently stole upon Plattsburg, which he found defended by less than a score of Federals, under the command of a lieutenant. The guerrillas dashed into the town about 3 P. M. (August 25th), yelling like a tribe of Comanche Indians. The citizens fled into their houses with such fear that few ventured to look into the streets even through key holes. The Federal lieutenant chanced to be in the public square when the charge was made, and Jesse James had the honor and credit of capturing him. The rest of the militia gained the court-house, where it would have been impossible to dislodge them, and to have attacked the building would have exposed the guerrillas to the fire of the enemy. It was here that Jesse James' strategy and military tact were first manifested. Turning his prisoner (the lieutenant) over to Captain Scott, he said in a loud voice: "Captain, there is no use parleying with these cut-throats; shoot this fellow if he don't order his men in the court-house to surrender immediately." Captain Scott replied that he would if the court-house was not surrendered in two minutes. The result was that Plattsburg fell into the hands of the guerrillas, who pillaged the town and gathered booty, consisting of two hundred and fifty muskets, several hundred rounds of ammunition, ten thousand dollars in Missouri warrants, besides a large quantity of clothing, etc. The money was divided among the participating guerrillas, each of whom received nearly one thousand dollars in warrants besides clothing and other articles of value. The guerrillas compelled the landlord of the principal hotel to prepare them a good supper, to which they invited their prisoners, whom they paroled; and after feasting until 9 o'clock P. M., they withdrew to the cover of the forest.

After raiding Plattsburg, Quantrell broke camp and moved southward, passing through Independence, and bivouaced near Lee's Summit. The residents of that section suffered pitilessly from the sack and pillage of both Federals and Confederates. They occupied a middle ground which was subject to the incursions of both armies, and what was left after the forage of the Union forces was remorselessly appropriated by the guerrillas. There were skirmishes almost daily, and every highway was red with human blood. The James boys, young as they were, became the terror of the border; the crack of their pistols or the whirr of their pirouetting bowies daily proclaimed the sacrifice of new victims. The sanguinary harvest grew broader as the sickle of death was thrust in to reap, and the little brooks and rivulets that had babbled merry music for ages and laved the thirst of man and beast with their crystal water, suddenly became tinged with a dye fresh from the fountain of bitterest sorrow. And thus the days sped on heavy with desolation. Quantrell and his followers were scarcely interrupted by the militia, who never attacked them except at the price of terrible defeat, until at length a direful scheme was proposed in which the desperate character of these free riders was manifested in its blackest hues.