...eces of cannon had been captured. At the hour when the letter was written McPherson's force, in the centre, was within one mile of the court house at Vicksburg, while Gen. Herman, on the right, and McClernand , on the left, were each within 1½ miles of the town, and the gunboats were shelling in front. It is believed Grant has nothing to fear from any concentration of forces in his rear. The des...