Mexico Illustrated in Twenty-six Views. John Phillips and Aldred Rider. Atchley, London. 1848
About 36 miles up from the National Road between Puebla and Mexico City lies the town of Rio Frio. located near the pass leading down into the Valley of Mexico. Here are seen Mexican infantry on march with an artillery unitcrossing the stream at Rio Frio. When the Americans reached the top of the pass just beyond Rio Frio they saw for the first time the great Valley of Mexico.
