...o Hamburg, some four miles above Pittsburg, when they all get here. From that point to Corinth the road is good, and a junction can be formed with the troops from Pittsburg at almost any point. Colonel McPherson has gone with an escort to-day to examine the defensibility of the ground about Hamburg, and to lay out the position of the camps, if advisable to occupy that place. U. S. Grant, Major-General. P...