[Sept. 12, 1847]
You will thus see the difficult and brilliant work our army has been doing. If Santa Anna does not surrender the city, or peace be negotiated, much more hard fighting may be expected, as I foresee, before the city is captured. My observations convince me that we have other strong works to reduce before we can enter the city. Our position is such that we cannot avoid these. From my map and all the information I acquired while the army was halted at Puebla, I was then, and am now more than ever, convinced that the army could have approached the city by passing around north of it, and reached the northwest side, and avoided all the fortified positions, until we reached the gates of the city at their weakest and most indefensible, as well as most approachable points. The roads and defenses I had carefully noted on my map, and I had communicated the knowledge I had acquired from Mexican scouts in our camp, and others I met at Puebla who were familiar with the ground, to such of my superiors as it seemed proper, but I know not whether General Scott was put in possession of the information. It is to be presumed however, that the commanding General had possessed himself of all the facts.
It seems to me the northwest side of the city could have been approached without attacking a single fort or redoubt, we would have been on solid ground instead of floundering through morass and ditches, and fighting our way over elevated roads, flanked by water where it is generally impossible to deploy forces.
What I say is entirely confidential, and I am willing to believe that the opinion of a lieutenant, where it differs from that of his commanding General, must be founded on ignorance of the situation, and you will consider my criticisms accordingly.
John W. Emerson, "Grant's Life in the West ...," The Midland Monthly, VII, 5 (May, 1897), 433.