In my letter to the Department, written the day after, I said I had expected that detachments of the new regiments would, as you had promised me, begin to arrive in this month, and continue to follow, perhaps, in June. How many volunteers will re-engage under the Act approved March 3d? I know not; probably but few. Hence, the greatest of my disappointments was caused by sending the new troops to the Rio Grande. For, besides their keeping the road in our present rear open for many weeks by marches in successive detachments, I had intended, as I advanced, to leave strong garrisons in this place (Jalapa), Perote and Puebla, and to keep at the head of the movement a force equal to any probable opposition. It may now depend on the number of the old volunteers who may re-engage, and the number of new troops that may arrive from the Brazos in time; as, also, in some degree, upon the advance of Maj.-Gen. Taylor, whether I shall find this army in strength to leave the garrisons, and to occupy the capital.
I may add that only about fifty individuals of old volunteers re-engaged under the provision of the Act of March 3d; that the remainder were discharged May 4th; that Maj.-Gen. Taylor made no movement in advance of Saltillo, and that the new regulars, including Gen. Cadwalader's brigade, only began to come up with me at Puebla, in July, but not in sufficient numbers till August 6th. The next day the army commenced its advance upon the capital, with a little more than ten thousand effective men. It is not extravagant to say that if Brig. Gen. Cadwalader's force had not been diverted from me to the Rio Grande; where he was made lose, without any benefit to Maj.-Gen. Taylor, much precious time, I might easily have taken this in the month of June, and at one-fifth of the loss sustained in August and September. The enemy availed himself of my forced delay at Puebla, to collect, to treble, to organize and discipline his forces. As, also, to erect numerous and powerful defences with batteries; nearly all those extraordinary preparations for our reception were made after the