The strategic importance that Gettysburg suddenly assumed during Lee's invasion of Pennsylvania, in July, 1863, first demands a little of our attention. Yet it seems certain that neither Meade nor Lee had thought of it as a possible battle-ground until accident thrust it upon them. At his first setting out on this campaign Lee had not been able to say, with the map before him, "I will fight a battle either in this or that place," because he had marched not toward, but away from, his adversary, and, so far as can be known, without choosing beforehand a position where Meade would have to come and attack him. For his part, so long as Meade was only following Lee about, the Union general cannot be said to have had much voice in the matter. It was Lee who was really directing Meade's march. True enough, Meade did select a battlefield, but not here, at Gettysburg; nor do we know, nor would it be useful to inquire, whether Lee could have been induced to fight just where Meade wanted him to. As Lee fought at Gettysburg only because he was struck, it is probably beyond any man's power to say that if this had not happened, as it did, Lee would have marched on toward Baltimore, knowing that Meade's army lay intrenched in his path. There is a homely maxim running to the effect that you can lead a horse to water, but cannot make him drink. The two generals, therefore, merely launched their columns out hit or miss, like men playing at blind-man's-buff. Gettysburg lies at the apex of a triangle of which Harrisburg and Baltimore form the base angles, at north and south--Harrisburg being only thirty-six and Baltimore about fifty miles distant. York and Carlisle also lie either on or so near this triangle as to come within its scope as a basis for military operations. Placed at Gettysburg, an army threatened all of these points. [Illustration: Diagram showing strategic value of Gettysburg. H., Harrisburg; G., Gettysburg; P., Philadelphia; Y., York; B., Baltimore; W., Washington.] [Sidenote: Topographical Features.] [Sidenote: Baltimore and Taneytown Roads.] [Sidenote: Cemetery Hill.]