After weeks of paralyzing siege, the Army finally abandoned the post, burning it as they evacuated. They retreated in the dark through a trench to the river, where they escaped on boats. The date of the abandonment is unknown, as much of the military correspondence from this period of the war is missing, but it probably happened in September. Black Hawk observed the ruins soon after. "We started in canoes, and descended the Mississippi, until we arrived near the place where Fort Madison had stood. It had been abandoned and burned by the whites, and nothing remained but the chimneys. We were pleased to see that the white people had retired from the country."