Whether Halleck planned this concentration of Grant's and Buell's armies for an advance upon Corinth as his partisans contend, or whether Grant planned it and Halleck merely accepted the plan as others stoutly assert, is a matter of no historical consequence, whatever biographical interest it may have. In either case the purpose of the concentration was to move upon Corinth in irresistible force, overthrow the Confederates there and seize upon the two important lines of railroad which intersect each other at that point. It was at any rate Halleck's purpose to command in this campaign in person. But it was not intended to advance upon Corinth until Grant's and Buell's armies should form a junction, and there was no thought or expectation that the Confederates would themselves assume the offensive. General Halleck planned to leave St. Louis not earlier than April 7, and perhaps several days later, for Pittsburg Landing. In the meanwhile General Grant had posted his army loosely and had thrown up no earthworks in the field. All his procedures indicated that he did not expect to be molested where he lay or to encounter the enemy until he should go in search of him. Indeed, he telegraphed Halleck on the fifth of April, the very day before the battle, saying, "The main force of the enemy is at Corinth, with troops at different points east.... I have scarcely the faintest idea of an attack (general one) being made upon us, but will be prepared should such a thing take place." At the very moment when that dispatch was penned the Confederates with their entire strength were actually on march to assail an enemy who had "scarcely the faintest idea of an attack" being made upon him either then or later. In his memoirs General Grant said: "When all reinforcements should have arrived I expected to take the initiative by marching on Corinth and had no expectation of needing fortifications.... The fact is I regarded the campaign we were engaged in as an offensive one and had no idea that the enemy would leave strong intrenchments to take the initiative when he knew he would be attacked where he was, if he remained." It had been the purpose of General Johnston to deliver his blow on the morning of the fifth of April, overthrow Grant, and be prepared to fall upon Buell when he should arrive. But matters of detail went so far wrong that the Confederates, advancing from Corinth to attack, did not reach the neighborhood of Shiloh church, where Sherman was posted without fortifications, until nightfall of that day. They bivouacked very near the Federal lines, but strangely enough their presence in force was not discovered by the enemy they purposed to fall upon at daylight. In the meanwhile the head of Buell's column had come up and the rest of it was dangerously near at hand.