If General Grant were here he'd attack instead of waiting to be attacked." But the Army of the Potomac continued to march forward in a slow and hesitating fashion.

Dick, despite his impatience, appreciated the position of General McClellan.

No one in the Union army or in the North knew the plans of Lee and Jackson.

Lee had not even consulted the President of the Confederacy but had merely notified him that he was going into Maryland.
Now Lee and Jackson had melted away again in the mist that so often overhung their movements.

McClellan could not be absolutely sure they intended an important invasion of Maryland.