...ither, however, has Gen. Pope. He knew at least two days before the battle that the rebels were marching to attack him; he knew that they had a very numerous force, and that it was under command of Stonewall Jackson , whose penchant for surprises and sudden movements is well enough known; he knew that Gordonsville and the line of the Rapidan would inevitably be contested to the last by the rebels. On Friday mor...