Winfield Scott’s army had not been idle since its victory at the battle of Cerro Gordo. After defeating Santa Anna’s forces, Scott’s Americans continued pushing further into the Mexican countryside. While there were small skirmishes as irregular Mexican forces nipped at the American soldiers, there were not any pitched major battles.
From the city of Jalapa Scott advanced his men to their next point, the city of Puebla. With hardly a shot fired, the vanguard of American soldiers entered the city nestled amongst the Sierra Madre mountains on May 15, 1847.
Puebla, a city of 80,000 people, offered Scott a site to halt his advance against Mexico City, 80 miles away. The city was firmly out of the vomito range—as the spring months gave way to summer, mosquitoes would increase, bringing deadly yellow fever. Away from the coast and up the mountains, Scott’s men would be shielded from the worst of the disease that could easily wipe out entire regiments, and at Puebla they could sit out the worst of the summer weather. Scott personally arrived at Puebla on May 28 to plan his army’s hiatus.
But other reasons gave Scott pause, and these were not nearly so practical as waiting out yellow fever. First, he did not have nearly enough men to keep pressing against Mexico City. Subtracting battle casualties, diseased men, and units detached to guard supply points, Scott could only count about 5,800 men left in his ranks. Scott later wrote, “Waiting for reinforcements, the halt, at Puebla, was protracted and irksome.”
But by far the most irksome to Scott was the presence of Nicholas Trist. A representative of the State Department headed by Sec. of State James Buchanan, Trist had been sent to Mexico to open a dialogue of ending the war. With the objectives of establishing a permanent national boundary along the Rio Grande River and getting most of what today is New Mexico and California, Trist had been authorized by Polk’s administration to spend as much as $30 million trying to accomplish those goals. On April 10, 1847, Polk appointed Trist, sending him off and also instructing “him to keep the matter a profound secret.” Trist began to make his way to Mexico with letters of introduction to both Scott and Mexican representatives.
The nearly 47-year old Trist arrived at Vera Cruz on May 6 extremely sick from the journey. Rather than go to see Scott in person, Trist forwarded a number of his letters to the general, but he forgot a copy written by Secretary Buchanan addressed to the Mexican minister of foreign affairs. That copy was supposed to go to Scott, explaining Trist’s mission, but the sick diplomat overlooked it.
While Trist tried to recover from his illness, Scott received the diplomat’s letters. One of the letters, directly from Sec. of War William Marcy, told Scott that if Trist made “known to you, in writing that the contingency has occurred. . . which the President is willing that further active military operations should cease, you will regard such notice as a direction from the President.” In other words, if Trist believed that if a peaceful armistice was close at hand and told Scott such, the commanding general were to take such a suggestion as if it came directly from President Polk.
When Scott read the letters, and in absence of Buchanan’s more-thorough explanation, he exploded. In words of early 20th-century historian Justin Smith, Scott was “an irascible, over-worked, over-worried soldier,” and the tension boiled over in the fury of his pen scratching across paper. “I see,” Scott fumed in a reply to Trist, “that the Secretary of War proposed to degrade me, by requiring that I, commander of this army, shall defer to you, the chief clerk of the Department of State, the question of continuing or discontinuing hostilities.” For good measure, Scott had a copy of the letter sent directly to Sec. of War Marcy.
In the meantime, Trist’s own temper got the better of him when he received Scott’s sarcastic answer so that when he finally joined Scott’s headquarters, the two did not arrange a meeting to see each other face-to-face and in fact did not bother to even speak to one another. So began the working relationship between the commander of the American army in Mexico and the diplomat sent to work out a peace. Eventually that relationship would patch itself, and will be the subject of a later post.
In the meantime, the American army settled itself into Puebla for what became a 10-week stay before resuming its advance against Santa Anna’s forces. American soldiers journeyed to nearby Aztec ruins, or bought local produce to supplement their army rations. It was a break from war, at least for the time being; the bloodiest fighting for Mexico City lay in the future.
 Timothy D. Johnson, A Gallant Little Army: The Mexico City Campaign (Lawrence: University Press of Kansas, 2007), 125.
 John S.D. Eisenhower, Agent of Destiny: The Life and Times of General Winfield Scott (New York: The Free Press, 1997), 261.
 Winfield Scott, Memoirs of Lieut.-General Scott (New York: Sheldon & Company Publishers, 1864), 453.
 Robert W. Merry, A County of Vast Designs: James K. Polk, The Mexican War, and the Conquest of the American Continent (New York: Simon & Schuster, 2009), 361.
 James K. Polk, The Diary of James K. Polk: During His Presidency, 1845-1849, Vol. II. Edited by Milo Milton Quaife (Chicago Historical Society: Chicago, 1910), 468.
 Merry, 366; Eisenhower, 262.
 Eisenhower, 263.
 Justin H. Smith, The War with Mexico, Vol. II. (The MacMillan Company: New York, 1919), 129.
 Eisenhower, 263.