The only thing about which he was neither apprehensive nor doubtful was his ability as a leader, whether military or political. While he found it difficult to impress his will upon an opponent in the field, he was very sturdy with his pen in laying down the law to the Commander-in-chief (the President) and in emphasising the importance of his own views not only in things military but in regard to the whole policy of the government. The peculiarity about the nightmares and miscalculations of McClellan was that they persisted long after the data for their correction were available. In a book brought into print years after the War, when the Confederate rosters were easily accessible in Washington, McClellan did not hesitate to make the same statements in regard to the numbers of the Confederate forces opposed to him that he had brought into the long series of complaining letters to Lincoln in which he demanded reinforcements that did not exist. The records now show that at the time of the slow advance of McClellan's army by the Williamsburg Peninsula, General Magruder had been able, with a few thousand men and with dummy guns made of logs, to give the impression that a substantial army was blocking the way to Richmond. McClellan's advance was, therefore, made with the utmost "conservatism," enabling General Johnston to collect back of Magruder the army that was finally to drive McClellan back to his base. It is further in evidence from the later records that when some weeks later General Johnston concentrated his army at Gaines's Mill upon Porter, who was separated from McClellan by the Chickahominy, there was but an inconsiderable force between McClellan and Richmond.