Later it was learned from traders out in the Indian country that the perpetrators of the deed were a party of Winnebago who had come into the neighborhood to "take some white scalps." Their plan had been to proceed down the river from Lee's Place and kill every white man outside the walls of the fort. However, hearing the report of the cannon, and not knowing what it portended, they thought it best to retreat to their homes on Rock River.
The settlers outside the fort, a few discharged soldiers and some families of half-breeds, now intrenched themselves in the Agency House. This building stood west of the fort, between the pickets and the river, and distant about twenty rods from the former.
It was an old-fashioned log house, with a hall running through the center, and one large room on each side. Piazzas extended the whole length of the building, in front and rear. These were now planked up, for greater security; portholes were cut, and sentinels posted at night.
As the enemy were believed to be still lurking in the neighborhood, or, emboldened by former success, were likely to return at any moment, an order was issued prohibiting any soldier or citizen from leaving the vicinity of the garrison without a guard.
One night a sergeant and a private, who were out on patrol, came suddenly upon a party of Indians in the pasture adjoining the esplanade. The sergeant fired his piece, and both retreated towards the fort. Before they could reach it, an Indian threw his tomahawk, which missed the sergeant and struck a wagon standing near. The sentinel from the blockhouse immediately fired while the men got safely in. The next morning traces of blood were found for a considerable distance into the prairie, and from this and the appearance of the long grass, where it was evident a body had lain, it was certain some execution had been done.
On another occasion Indians entered the esplanade to steal horses. Not finding any in the stable, as they had expected to, they relieved their disappointment by stabbing all the sheep in the stable and then letting them loose. The poor animals flocked towards the fort. This gave the alarm. The garrison was aroused, and parties were sent out; but the marauders escaped unmolested. The inmates of the fort experienced no further alarm for many weeks.
On the afternoon of August 7, Winnemeg, or Catfish, a Potowatomi chief, arrived at the post, bringing dispatches from General Hull. These announced that war had been declared between the United States and Great Britain, and that General Hull, at the head of the Northwestern army, had arrived at Detroit; also, that the Island of Mackinac had fallen into the hands of the British.
The orders to Captain Heald were to "evacuate the fort, if practicable, and, in that event, to distribute all the United States property contained in the fort, and in the United States factory or agency, among the Indians in the neighborhood."
After having delivered his dispatches, Winnemeg requested a private interview with Mr. Kinzie, who had taken up his residence in the fort. He told Mr. Kinzie he was acquainted with the purport of the communications he had brought, and begged him to ascertain if it were the intention of Captain Heald to evacuate the post. He advised strongly against such a step, inasmuch as the garrison was well supplied with ammunition, and with provisions for six months. It would, therefore, be far better, he thought, to remain until reinforcements could be sent. If, however, Captain Heald should decide to leave the post, it should by all means be done immediately. The Potowatomi, through whose country they must pass, being ignorant of the object of Winnemeg's mission, a forced march might be made before the hostile Indians were prepared to interrupt them.
Of this advice, so earnestly given, Captain Heald was immediately informed. He replied that it was his intention to evacuate the post, but that, inasmuch as he had received orders to distribute the United States property, he should not feel justified in leaving until he had collected the Indians of the neighborhood and made an equitable division among them.