In late April of 1847, at the height of the Mexican-American War, General Winfield Scott, the commander of the campaign to seize Mexico City, asked General Zachary Taylor for mounted units to fight guerrillas attacking U.S. supply convoys along the vital logistics route stretching from Veracruz to Puebla. Scott did not specifically request Texans but simply wrote he needed “a competent fighting force” of cavalry units. Having experienced cavalry-centric “Indian” warfare for a generation in the borderlands, the Texas Rangers were aptly suited for the role. Motivated and hardened after years of defending the Republic of Texas the frontier fighters were authorized by federal officials to enter the war as militia operating under a semi-separate set of laws governing military conduct. This designation legally complicated the population-centric counterinsurgency efforts Scott and West Point-trained officers were attempting to instill within the U.S. Army. The dichotomy between the battlefield efficacy of the Texans and their frequent noncompliance with the laws of war is best described by historian Major Ian B. Lyles as a “mixed blessing.” Nevertheless, Scott’s ability to control the Rangers were limited given their official status as militia operating under the auspices of the U.S. President and Commander-in-chief James K. Polk. In this regard, the developing laws of war and presidential war powers played an important but overlooked role in the U.S. Army’s first foreign war.[1]

Anglo-American Laws of War

Origins of U.S. Army military jurisprudence originate from England. In 1806, with minor deviations, the U.S. Congress formally adopted the English laws of war. Those Articles of War – an addition to the Uniform Code of Military Justice (UCMJ) established in 1775 by the Second Continental Congress during the American Revolution – dealt primarily with policing and managing armies. While English and later U.S. law was based on national law, works informed by jurists Hugo Grotius and Emer de Vattel were focused on creating international law. This parallel legal development (i.e. international and domestic) is important because the Anglo-American legal code regulating the conduct of armies later became a major contributing factor in the international legal framework later embodied in Geneva Convention articles designed to protect the welfare of noncombatants during wartime. When the U.S. Congress adopted the English laws of war the rights of militiamen (i.e. nonregulars) during wartime became a part of those laws informing the future development of the UCMJ.[2]

Laws regulating militias had been around in England since the restoration of Charles II (1660) and were passed on to colonial America. Like the original intentions of the English, the U.S. laws organizing and regulating militias were primarily a mechanism for amassing armies quickly to defend a territory from invasion or put down internal insurrection. As the U.S. military professionalized during the antebellum period, the antiquated system of separate laws that state militiamen were held accountable to during wartime became an issue because the war in Mexico was a war of conquest on foreign soil.[3] In 1919, Paul Tincher Smith commented on the May 2, 1792 federal act passed by the U.S. Congress regulating the organization of militias in the United States – arguing that it “deserves such examination in detail because it covers the field of possibilities in organization so thoroughly that there was little left for the individual States to decide.” In essence, the law that remained in effect at the start of the Mexican War in 1846 was used by Polk (i.e. the federal government) to enlist soldiers. Tincher wrote:   

The basic law… was entitled, ‘An Act to provide for the Militia to execute the laws of the Union, suppress insurrections and repel invasions.’ Although probably suited to the time when it was made, it left many loopholes which had to be filled in later… in 1808 the President was given authority to require executives of the States to organize effectually and equip their portion of the militia, and the government agreed to provide the equipment for all militiamen, the allotments to be based on the annual returns. In 1820 the States were required to use the discipline and yield exercise of the regular army. This completes the government program to the beginning of the Mexican war.[4]


Top photo: Company of the Frontier Battalion, Texas Rangers, c. 1885. Source: Wikimedia. In the Public Domain.

Middle photo: Colonel John Coffee "Jack" Hays (January 28, 1817 – April 21, 1883). Source: Wikimedia. In the Public Domain.

Bottom photo: Winfield Scott on horseback. Caption reads, "GEN SCOTT AT THE BATTLE OF CERRO GORDO." Source: Wikimedia and Flickr. In the Public Domain.


“They have come out as militia”

Since Texas bordered Mexico the use of militia during the war impacted the northern theater under Taylor’s command more than any other region under American occupation. The issue reached a critical moment in mid-1847 when the dominance of U.S. forces became clear. On June 26, 1847, Secretary of War William Marcy informed Taylor that Texans showing up for duty were responding to calls by Colonel Samuel R. Curtis – the former military governor of Camargo who fought off attacks by General Urrea’s cavalry and ranchero units during the Buena Vista campaign. During that engagement, Curtis reported that Taylor’s army was surrounded and needed thousands of additional troops. Marcy told Taylor he was “at a loss to determine what ought to be done” with the extra mounted units, but that he was authorized by President Polk “to retain them,” if necessary. The catch was, the regiment reporting for duty under the command of Colonel John Coffee “Jack” Hays, was neither enlisted nor volunteer, but Texas militia. Marcy explained to Taylor that forces were enlisted under the belief “the Rio Grande frontier was exposed to invasion,” which justified the use of the militia by the President to defend the border based on the act of Congressional approval for the war May 13, 1846. Marcy wrote: "That call was made under the apprehension that the Rio Grande frontier was exposed to invasion, and that the act of the 13th of May, 1846, section second, declares “that the militia, when called into service of the United States by virtue of this act, or any other act, may, if in the opinion of the President of the United States the public interest requires it… They have come out as militia, as distinguished from volunteers…"[5]

12439921258?profile=RESIZE_400xAlthough the U.S. Constitution addressed presidential war powers relating to the militia, what Marcy referred to directly in his letter to Taylor was the “declaration of war” against Mexico made by Congress May 13, 1846. The authority expressly given to the president in that congressionally approved act was predicated upon the original Articles of War but differed in that the enlistment period for the militia during the Mexican conflict was specifically set at six months. What was not clear was how the Texans could be employed as militia in the heart of Mexico. According to the Constitution, militia only had the legal authority to repel invasion (as Marcy noted), and in the north the rationale was they were defending Texas. Central Mexico was quite far from the Rio Grande. Where exactly the borders of Texas ended was key, and the legal slight-of-hand was that if Texas territory included all of northern Mexico, then any part of that country could theoretically be defended by Texas militia operating under presidential authority. In short, their enlistment in central Mexico appeared to be stretching war powers. By using the militia clause Polk discovered a way to undermine Scott’s authority in Mexico by invoking the expressed powers of the commander-in-chief outlined in the Articles of War. Article 62 specifically addressed presidential powers: "If upon marches, guards, or in quarters, different corps of the army shall happen to join, or do duty together, the officer of the highest in rank of the line of the army, marine corps, or militia, by commission there, on duty, or in quarters, shall command the whole, and give orders for what is needed to the service, unless otherwise specially directed by the President of the United States, according to the nature of the case."[6]

Even though the Texans under Hays believed they were operating under the explicit authority of presidential powers in the Articles of War, Marcy’s language in his instructions to Taylor muddied the issue. Marcy informed Taylor he was authorized by the president to retain the companies “raised under” Colonel Curtis “as militia, for six months.” However, in the following paragraph the Secretary of War put the onus on Taylor to determine the status of the Texan cavalry volunteers. “Should they, or a considerable portion of them, be willing to become volunteers,” he wrote Taylor, “if it is only for twelve months, it is decidedly preferable that they should be engaged as such, instead as militia. This matter, under the foregoing views, is left to your discretion.” Marcy dropped the decision in Taylor’s lap, and not surprisingly it was Taylor who left it to the Texans to decide for themselves their official status.[7]

Polk's Choice

So how did Colonel John Coffee “Jack” Hays receive authority to enter the war as a counterinsurgency officer while classified as militia? Polk made the decision sometime after March 19, when Hays, Polk, and two other officers “took a family dinner” together in Washington DC. On July 10 Polk wrote in his diary, “I sent for the Secretary of War this morning and conferred with him upon the necessity of speedily reinforcing Gen’l Scott’s column, and especially of opening his communication with Vera Cruz.” Polk wrote that Hays enjoyed “a high character as an officer” and may have initially learned about him from reports before and during the war. “I suggested that the mounted Regiment from Texas under the command of Col. John C. Hays,” he wrote, “be ordered to proceed without delay to Vera Cruz to co-operate with other troops in dispersing the bands of guerrillas who infest the road from Vera Cruz in Gen’l Scott’s rear.”[8] 

The early twentieth-century Mexican War historian Justin Smith stated “Polk himself selected Hays’s” unit. The unit was well known – appearing in numerous reports on the war, particularly surrounding the Battle of Monterrey in September of 1846. Although the unit was exceptionally gifted in battle, one of the differences between Hays and Samuel H. Walker, another famous Texas Ranger in the Veracruz-Mexico City campaign, was that “Walker, though stern with the guerrillas, would not permit his men to pillage.” Hays’s unit had a reputation. Smith also described the Texans’ eclectic, if not unprofessional, appearance: “Hays’s Rangers seemed to aim to dress as outlandishly as possible, and with their huge beards looked almost like savages.” Indeed, there was nothing conventional looking about the frontier fighting unit. According to Colonel Ethan A. Hitchcock, the U.S. Army’s inspector general and one of Scott’s essential intel officers in the Mexico City campaign, none of the Texans wore “any sort of uniform,” but were “well mounted and doubly armed: each man has one or two Colt’s revolvers besides ordinary pistols, a sword, and every man his rifle.” The irregular appearance of the Rangers to the New England West Point graduate was more mercenary than soldier. “All sorts of coats, blankets, and head-gear, but they are strong athletic fellows. The Mexicans are terribly afraid of them.”[9] Indeed, they were the embodiment of the frontier fighter and, in many ways, the opposite of West Point graduates.  

The unit that went to Mexico under the command of Colonel Hays was designated the 1st Regiment of Texas Volunteers, which, if truly volunteers, would have obligated them for service for twelve months. However, the last counterinsurgency engagement of the war for the Rangers under Hays’s command occurred on February 25, 1848 – a date just under the six-month period of enlistment as militia. The guerrilla war in central Mexico, which began after the Mexican defeat at Cerro Gordo in April, did not end late February, nor after a general armistice between U.S. and Mexico was signed almost a year later in early March. The Texans – who were aware of their status as militia – were obligated to either quit or reenlist. If they had been volunteers, their valuable services might have been retained longer than six months because at that point the Americans still had not rid central Mexico of guerrillas still operating in the area. The Texans may have called themselves volunteers, but in Marcy’s words they were “militia, as distinguished from volunteers…”

12439999101?profile=RESIZE_584xIn his Memoirs, Winfield Scott commented on the legal grey area concerning the militia and cited Section Eight of the U.S. Constitution to argue that militia were expressly organized for the purpose of national defense. “The militia, by the previous article 1, section 8, can only be called out ‘to execute the laws of the Union, suppress insurrections, and repel invasions.’”[10] In other words, the militia did not have the authority to invade other countries, much less operate on foreign soil. The case in point with the Texas regiment was singularly unprecedented. In effect, they were beyond the law, and seemingly beyond Scott’s authority. 



[1] House Executive Document (subsequently: HED) No. 60, 1171–2. (Library of Congress). Scott (at Jalapa) to Taylor (near Monterrey) April 24, 1847; Major Ian B. Lyles, Mixed Blessing: The Role of The Texas Rangers in The Mexican War, 1846-1848, (Normanby Press, 2015); Benjamin J. Swenson, “‘Measures of Conciliation’: Winfield Scott, Henry Halleck, and the Origins of US Army Counterinsurgency Doctrine,” Journal of Military History 86, no. 4 (Oct. 2022): 859-881. See: Robert Utley, Lone Star Justice (New York: Berkley Publishing Group, 2002); Michael Collins, Texas Devils Rangers & Regulars on the Lower Rio Grande, 1846-1861 (Norman: University of Oklahoma Press, 2008); Nathan A. Jennings, Riding for the Lone Star: Frontier Cavalry and the Texas Way of War (Denton: University of North Texas Press, 2016).  

[2] Grotius, Hugo. On the Law of War and Peace (De jure belli ac pacis librites), 1625; Emer de Vattel, The Law of Nations, or, Principles of the Law of Nature, Applied to the Conduct and Affairs of Nations and Sovereigns, 1758. (Philadelphia: T. & J.W. Johnson, Law Booksellers, 1852).

[3] J.R. Weston, The English Militia in the Eighteenth Century: The Story of a Political Issue, 1660-1802 (London: Routledge, 1965); Matthew McCormack, Embodying the Militia in Georgian England (Oxford: Oxford University Press, 2015); John K. Mahon, History of the Militia and the National Guard (New York: Macmillian, 1983); Robert W.T. Martin, Government by Dissent: Protest, Resistance, and Radical Democratic Thought in the Early American Republic (New York: New York University Press, 2013). See also: Federalist Papers (1787) No. 29 “Concerning the Militia” (Alexander Hamilton), No. 46 (James Madison); U.S. Constitution Article I Section 3, Article II Section 2, Clause 3.

[4] Paul Tincher Smith, “Militia of the United States from 1846 to 1860,” Indiana Magazine of History 15, no. 1 (March 1919), 28, 21.

[5] HED No. 60, 1191-1192. Marcy (Washington D.C.) to Taylor (Monterrey), June 26, 1847.

[6] U.S. Articles of War (Art. 62), Annals of Congress, 9th Congress, 1st Session, March 29, 1806. Appendix: “Public Acts of Congress”, Washington D.C., Library of Congress, 1246.

[7] HED No. 60, 1191-1192. Marcy (Washington D.C.) to Taylor (Monterrey), June 26, 1847.

[8] Milo Quaife (ed.), The Diary of James J. Polk During his Presidency, 1845-1849, vol. 2,3 (Chicago: A.C. McClurg & Co., 1910), 429 (vol. 2), 89 (vol. 3). March 19, July 16, 1847, respectively.

[9] Justin H. Smith, The War with Mexico, vol. 2, (New York: Macmillan, 1919), 423; Ethan Allen Hitchcock, Fifty Years in Camp and Field (New York: Ed. W.A. Croffut. G.P.  Putnam’s Sons, 1909), 310.

[10] Lieutenant General Winfield Scott, Memoirs (New York: Sheldon, 1864), 291.

You need to be a member of War History Network to add comments!

Join War History Network

Votes: 0
Email me when people reply –