The interval was occupied in continual skirmishes and reconnoissances. Meanwhile Crook changed over from the left flank to the right at Summit Point, the cavalry covering the front and flanks from Snicker's Gap by way of Smithfield and Martinsburg to the Potomac. On the 16th of September, Grant, pressed by the government in behalf of the business interests disturbed by the enemy's control of the railway and the canal, went to Charlestown to confer with Sheridan. In the breast-pocket of his coat Grant carried a complete plan of the campaign he meant Sheridan to carry out; but when, having asked Sheridan if he could be ready to move on Tuesday, Sheridan promptly answered he should be ready whenever the General should say "Go in"--at daylight on Monday, if necessary,--so delighted was Grant that he said not a word about the plan, but contented himself with echoing the words, "Go in!" (1) Grover's men made the hard march of 69 miles from Washington in three days; the last 33 miles in 13½ hours, actual time. See Major Tiemann's "History of the 159th New York," pp. 91, 92. CHAPTER XXXII. THE OPEQUON.(1) Grant's approval of Sheridan's attack was founded on the withdrawal of Kershaw; but on the 18th of September, just as Sheridan was about to move on Newtown, meaning to offer Early the choice of being turned out of Winchester, or being overwhelmed if he should stay, news came from Averell that he had been driven out of Martinsburg by two divisions of infantry. These were the divisions of Rodes and Gordon, with which, enticed at last into a grave error by the temptation of hearing that the railway was being repaired, Early had marched on the 17th to Bunker Hill and Martinsburg. When Sheridan heard of this, and perceived that Early's forces, already diminished, were strung along all the way from Winchester to Martinsburg, he stopped the execution of the orders he had already issued for the movement at four o'clock in the afternoon of that day, the 18th of September, and replaced them by fresh arrangements which led to the battle of the Opequon on the 19th. Since last moving to the Clifton-Berryville line, Sheridan had used his cavalry to preserve in his front an open space fully six miles in depth, extending to the banks of the Opequon, meaning not only to have the first tidings of any offensive movement by the enemy, but also that when himself ready to move he might be able to take the enemy by surprise. On the evening of the 18th of September, part of Early's cavalry was at Martinsburg, Gordon occupied Bunker Hill, Wharton was at Stephenson's, with Rodes closing back on him, while Ramseur alone covered Winchester in the path of Sheridan's advance. Sheridan naturally supposed that in a quick movement he would have two divisions to deal with after crossing the Opequon.