He resolved that, rather than remain in prison, he would go alone.

He grew stronger every day, and succeeded in securing a pair of shoes, and a compass, for which he gave the last shirt he had.

His determination was to take to the woods, until he had escaped pursuit, and then strike for Red River.
He knew that this route would bring him out a good distance below Vicksburg, but still it would be easier and safer than traveling across the country; and he hoped that the rebel stronghold would be taken by the time he reached the Mississippi River.
Finally, one dark night--after he had well matured his plans--he concluded to make the trial.

So, waiting until every one in the room appeared to be asleep--for he had been told that there were some who must know nothing of his intention--he carefully raised one of the windows, and looked out.

He had made all his observations beforehand, and knew that the window was about twenty feet above the ground.