Lee in Pennsylvania was in the midst of a very hostile population and facing superior forces which he could only defeat in one of two difficult ways: either by a sudden, bewildering, and unexpected attack, like Jackson's and his own at Chancellorsville, or by an impregnable defense on ground that also favored a victorious counter-attack and the subsequent crushing pursuit. But there was no Jackson now; and the nature of the country did not favor the bewildering of Federals who were fighting at home under excellent generals well served by a competent staff and well screened by cavalry. So the "fog of war" was quite as dense round Lee's headquarters as it was round Meade's on the first of July, when Lee found that his chosen point of concentration near Gettysburg was already occupied by Buford's cavalry, with infantry and some artillery in support. The surprise--and no very great surprise--was mutual. The Federals were found where they could stand on their defense in a very strong position if the rest of their army could come up in time. And Lee's only advantage was that, having already ordered concentration round the same position, he had a few hours' start of Meade in getting there. Each commander had intended to make the other one attack if possible; and Meade of course knew that Lee, with inferior numbers and vastly inferior supplies, could not afford to stay long among gathering enemies in the hostile North without decisive action. The Confederates must either fight or retreat without fighting, and make their choice very soon. So, when the two armies met at Gettysburg, Lee was practically forced to risk an immediate action or begin a retreat that might have ruined Confederate morale.