If, on the other hand, we could move eastward along the railroad, we could bring our supplies to our camps as we advanced. Sherman's army behind us would make our base at Chattanooga safe; the great mountain barrier on the right would so cover our flank that scarce any force need be left in Tennessee, but all could be put in the aggressive column: the troops in Kentucky could be brought forward as we progressed, for our movement would cover that district; finally, on reaching the New River valley we could be joined by the forces in West Virginia. The advance, therefore, instead of being with a dwindling column would be with a growing one, and when the Army of the Potomac should approach the valley of the James, we should be ready with about forty thousand to come into line as the right wing of that army. Approaching Richmond from the north and west, the south side railroad would be at once in our grasp, and that to Petersburg within easy reach. The objection to such a plan which would first occur to a critic, would be that convergent movements from so distant bases are proverbially uncertain; but this objection is greatly weakened by a study of the topography of the country. The Holston valley is so isolated that, approached by the railway line with a good base behind the column, it is strongly defensible, and if the advance is so timed as not to pass the New River before the Army of the Potomac should be swinging in toward Richmond from the northwest, Lee's army would be too fully occupied to make a detachment strong enough to oppose us, and the line by which he would operate against us would be threatened by the army of our friends. There would also be a safe line of retreat always open for us, in case of check. [Footnote: Napoleon was a master of strategy who fully appreciated the objections to exterior lines, but in the campaign of Wagram in 1809 he ordered Marmont to lead a column from Italy to Vienna by a route having strong resemblances to that which I have sketched. He regarded the character of the route itself, protected as it was by mountain ranges, and giving the assurance of a line of retreat, as making an exception to ordinary cases and overcoming the objections which would have been conclusive against attempting it in an open country.] Another interesting feature in this plan is that if railway communication between Sherman and the Potomac Army had been opened in the summer of 1864, it would have been an interior line of immense importance, not improbably modifying essentially the final campaign of the war.