With these September days came the climax of the aggressive Free-State campaign. Also, came the collapse of the pro-slavery effort to fasten slavery upon Kansas by force of arms. Lawrence was the headquarters for the Free-State men, and their activities gave to the place an atmosphere of war. Lane led an expedition against Atchison's army which he encountered at Bull Creek. September 7th, the day Brown arrived from Osawatomie, an expedition was launched against Leavenworth, under the command of Colonel James A. Harvey, but it was ordered back to Lawrence, by General Lane, before it arrived at its destination. On September 9th, General John W. Geary arrived in the Territory. He had been appointed Territorial Governor to succeed Governor Shannon.
"Almost simultaneously with Harvey's movements, Aaron D. Stevens, alias Charles Whipple, raided Osawkie, a pro-slavery settlement, taking eighty horses and nearly as many arms."[209] Falling back from the front of Atchison's army at Bull Creek, Lane personally led an attack upon Hickory Point, and finding the pro-slavery men too strong, sent to Lawrence for assistance. "Whipple and fifty men responded; but on their arrival Lane wanted Bickerton's cannon, and sent to Lawrence for it." Colonel Harvey, who had just got back from the Leavenworth campaign, also went to his assistance, arriving on the 14th. Lane in the meantime had abandoned the siege, but Harvey attacked them at once, and after a spirited fight captured the force. His loss was five men wounded. The pro-slavery loss was one man killed and four wounded. There was no robbery involved in this battle.[210] Later, Captain Wood, United States Army, met and captured one hundred of Harvey's men including their arms, and the cannon.
The withdrawal of Lane from Lawrence, with a large portion of the organized Free-State forces, left the town quite unprepared to resist the advance against it by General Atchison's army, which arrived at Franklin on the 13th. This was the most formidable force that had ever invaded the Territory. It comprised, at this time, twenty-seven hundred men, including a battery of artillery. The principal subordinate commanders were Generals John W. Reid, B. F. Stringfellow, W. A. Haskell, and J. W. Whitfield. On the afternoon of the 14th, Atchison made a reconnoissance, his advance guard drawing the fire of the Free-State pickets in front of Lawrence. His attack upon the town on the morning of the 15th, was prevented by the armed intervention of the Federal Government. During the night of the 14th, detachments of United States cavalry and artillery arrived at Lawrence, and took up positions to defend the town. The Territorial Governor, Geary, appeared upon the scene on the morning of the 15th, and, proceeding to Atchison's camp, notified him that he could proceed no farther. This forceful intervention was fatal to the pro-slavery propaganda. Upon receiving the Governor's ultimatum, the pro-slavery leaders disbanded their army and gave up the struggle. Geary's interference was not wholly unexpected. The "hand writing" had heretofore been seen "upon the wall." Before Atchison's advance upon Lawrence, a South Carolinian, connected with the invading army, stated the situation in this way: "And why should we remain? We cannot fight, and of course, cannot prevent our enemy from voting. The object of our mission will then, of course, be defeated and we had as well return."[211]