Like the Americans in the Revolutionary War (1775–83), Mexicans during their war of independence (1810–21) were labeled “traitors” and “rebels,” but a new designation arose out of the emergence of a novel system of insurgent warfare originating in Spain. The Patriot Wars in the Gulf coincided with the advent of modern “guerrilla” warfare, which initially affected how Mexicans were depicted in the press until the U.S. government formalized nomenclature in support of the revolutions there and elsewhere in Spanish America by adopting the term “patriot.” In short, the new (and illegal) mode of warfare was downplayed in favor of the more politically palatable and propagandist term invoking the spirit of radical republicanism opposed to European monarchical rule. Nevertheless, usage and adoption of the Spanish guerrilla “system,” which Americans were already familiar with given their revolution and encounters with Native Americans employing similar tactics, altered the military dynamics of the conflict throughout Mexico and the Gulf. Just like the American Revolution, guerrilla warfare played a prominent role in achieving independence.^[1]   

Right: On 28 September 1810, Hidalgo led the siege of the Alhóndiga de Granaditas in Guanajuato. The Combat of the Alhóndiga de Granaditas in Guanajuato on September 28, 1810, Oil on Canvas, José Díaz del Castillo, 1910. Archive/Collection: Institute of Culture of Morelos. Source Wikimedia. Click to expand.

In 1809, one year after the beginning of the Napoleonic War in Spain, there was little reference to “guerrilla” war and what limited references existed demonstrate that the term was entirely novel. In November of that year, after the Spanish formalized the new system with the creation of the Corso Terrestre (land privateering), London’s Morning Chronicle noted a story from Bordeaux citing “guerrillas, or skirmishes, which is the mode of warfare the Spaniards have now adopted.” Apart from skirmishing, the article was short on details of what that mode tactically meant, but the term “guerrilla” at that point did not appear in U.S. newspapers. In 1810, references to “guerrillas” and “guerrilla war” in British newspapers increased dramatically. This was due to the time delay in receiving news from the peninsula, and because, by the fall of 1809, the efficacy of the insurgency mounted against Napoleon was beginning to garner attention outside Spain.^[2]

It was not until the fall of 1810 that the word “guerrilla” began appearing in U.S. newspapers and by 1811, when the Mexican War of Independence was well underway, the term “guerrilla” was ubiquitous among the British but still in the process of being disseminated in the United States. Nevertheless, information on the Spanish insurgent war was beginning to make its way across the Atlantic. The usual London papers kept abreast of guerrilla actions on the peninsula while Americans slowly learned of what transpired in Spain and Mexico. In spite of the outbreak of the War of 1812, knowledge of the new style of warfare percolated into the United States. The fact that Europeans adopted a type of warfare utilizing Native American tactics also leant it legitimacy. For example, the Pennsylvania Gazette published a story in February 1812 noting that the French “situation in that country grows every day more insupportable to them, on account of the numerous bodies of guerrillas, which, harassing their foraging parties everywhere, put them under the necessity of scattering their forces.”^[3] 1812 was also the year the word “chief” began its common association with “guerrilla.” This connotation denoted a fusion between the term in North America as it related to Native American tribes and the comparative methods the Spanish were employing against the French. Others used the term “principal chiefs of the guerrillas” to describe them. By the spring of 1813, then, there was general knowledge that in Spain there were “several large divisions of guerrillas, which are spread all over the peninsula.”^[4]

By 1814 the terms “guerrilla chief” and “guerrilla warfare” made their way into the general lexicon.^[5] The term “Guerilla Chief” was even used as the title of an 1815 romance novel set in Spain by Emma Parker and published in London. However, Parker did not use the term “guerilla chief” until the third volume of her story, implying it was still uncommon in England until 1814.^[6] As the term came into limited usage among the literati, it was shelved briefly and revived to describe independence fighters in Spanish America. The British, with their large contingent of soldiers in Spain, were more informed of guerrilla warfare, which their forces used for critical intel, and initially looked at events unfolding in the Americas from that perspective:

Above: Among the most extraordinary and intricate artistic representations of Mexico's struggle for independence is a mural created by the renowned artist Juan O’Gorman. This masterpiece, painted between the years 1960 and 1961, stands as a vivid and powerful tribute to the nation’s fight for freedom. The mural is housed in the Museum of National History, located within the historic Castillo de Chapultepec in Mexico City. This castle, perched atop Chapultepec Hill, serves as a significant cultural and historical landmark, making it a fitting home for O’Gorman’s work. The mural not only captures the dramatic events of the independence movement but also reflects the artist’s unique style and deep connection to Mexico’s history and identity. In the public Domain.

New Spain, is exactly the same as that of Old Spain in the late war; the Royalists possess only the capitals of provinces, in which they are obliged to keep many troops to maintain internal order, and keep their communications open as well as they can. They can hardly venture into the field, …their advanced posts are frequently attacked, as was lately the case with the outworks the Viceroy had established two miles from Mexico. The insurgents are completely organized into strong guerrillas and parties, and nothing Royalists can traverse the roads without covering troops.^[7]

With first-hand knowledge of the guerrilla war in Spain, it was the British who frequently employed the word “guerrilla” to describe the independence movements in Spanish America. The term was used because Mexican insurgents employed similar unconventional tactics. On the other hand, Americans were anathema to monarchy and usually (although not exclusively) referred to the revolutionaries fighting for independence as “patriots” or “republicans.” While the British were using the term “guerrillas” to describe insurgents in Mexico, after 1815 they also began employing the term “patriots” – reflecting a changing position regarding Spanish possessions in the Americas. In contrast, the Americans referred to the Mexican revolutionaries as “patriots” as early as 1812, but appreciated the British change in position. Thus “patriot” in the Anglosphere meant something entirely different than the invocation of “patria” in Spain or Spanish America – which denoted loyalty to the crown, the mother country, and one’s local regional familial network. It took on the opposite political meaning in the U.S. from an early period and in Britain after 1815.^[8]

From a U.S. point of view, Spanish American insurgents, whom Americans frequently referred to as their ‘brethren,’ were spreading the sphere of liberty and republicanism in the western hemisphere. Henry Clay, Speaker of the U.S. House of Representatives and a prominent formulator of policy during the period, made efforts in 1818 to ensure the preferred nomenclature was codified in government statements. While describing this policy he noted that the “committee will remark that the document does not describe the patriots as rebels or insurgents, but using the term” that he “well weighed” for maximum ideological effect. In a March 1818 speech titled, “On the Emancipation of South America,” Clay outlined America’s “peculiar interest” in the “immense country watered by the Mississippi” and Mexican independence, noting that Mexico was “not a dangerous neighbor at present, but… her power may again be resuscitated. Having shown that the cause of the patriots is just, and that we have great interest in its successful” outcome. Regarding Clay’s statement, most Americans used the term ‘South America’ when referring to any Spanish territory south of the United States – including Mexico.^[9] 

Ideology and geopolitics were the principal reasons Americans supported revolution in Mexico, and Monroe later issued his anti-monarchist ‘doctrine’ directed at the Holy Alliance (France, Austria, Prussia, and Russia) in his 1823 annual message to Congress after Mexico achieved its independence. Thus news of the rebellions embroiling Mexico and South America relegated the tactical novelty and use of guerrilla war. The focus instead was put on the “patriot” (i.e. republican) cause of the revolutionists, which was the larger and more important story. It was no longer depicted as a David versus Goliath-like struggle that characterized the Spanish war against Napoleon, and since the “patriots” were guerrillas employing unconventional tactics to achieve military victories, their illegal mode of warfare was downplayed or ignored altogether. The press perspective, rather than being militarily oriented, was depicted through a political prism akin to the American Revolution.

[1] See: Benjamin J. Swenson, The Dawn of Guerrilla Warfare: Why the Tactics of Insurgents against Napoleon failed in the US Mexican War (Barnsley, UK: Pen and Sword, 2023). This article, which has been slightly amended, is an excerpt from: Benjamin J. Swenson, America and Mexican War of Independence: Insurgents, Patriots, and Brethren in Arms, 1810 –1821 (Jefferson, NC: McFarland, 2025).

[2] Morning Chronicle, London, Nov. 8, 1809. The Bordeaux citation is dated Oct. 25; Caledonian Mercury, Edinburgh, July 28, 1810; Morning Post, London, Aug. 30, 1810 (Reprinted in Jackson’s Oxford Journal, Sept. 1, 1810; Freeman’s Journal, Dublin, Sept. 4, 1810; Hull Packet, Sept. 4, 1810); The Times, London, Sept. 15, 1810; Cobbett’s Weekly Political Register, London, Sept. 19, 1810; Morning Post, London, Oct. 4, 1810; Hull Packet, Oct. 30, 1810; Morning Chronicle, London, Sept. 3, 1810. Other mentions of ‘guerrillas’ were Derby Mercury, Oct. 11, 1810; The Observer, London, Oct. 28, 1810.

[3] Pennsylvania Gazette, Philadelphia, Feb. 19, 1812. (Lisbon, Dec. 12); British newspapers using the term “guerrilla” include (1811): The Times, London, Aug. 7, Aug. 31, Sept. 16, Sept. 19, Oct. 17; Morning Post, London, Feb. 11, July 27, Oct. 28, Oct. 31; Freeman’s Journal, Dublin, May 23, July 17; Hull Packet, Jan. 22, The Derby Mercury, Aug. 1; Morning Chronicle, London, June 26, July 29.

[4] Buffalo Gazette, Sept. 8, 1812; Pittsburg Gazette September 11, 1812. See also: Caroline Federal Republican, New Bern, March 28, 1812. Pennsylvania Gazette, Philadelphia, April 28, 1813; Vermont Journal, Windsor, May 3, 1813; The Adams Sentinel, Gettysburg, May 5, 1813; Pittsburg Gazette, May 7, 1813; Buffalo Gazette, May 11, 1813.

[5] The Times, London, March 1, 1814; Jackson’s Oxford Journal, March 5, 1814; The earliest reference to the two-word term guerrilla warfare is in The Times (London) July 5, 1813. “That mass [French army] has been diminished by sickness, by the continued drain of the guerrilla warfare, and by the drafts made by the German campaign.”

[6] Emma Parker, The Guerilla Chief, 3 vols. (London: William Lindsell, 1815). 

[7] Morning Chronicle, London August 15, 1815.

[8] For early ‘patriot’ references in the Mexican Revolution is U.S. papers see: Missouri Gazette, St. Louis, September 12, 1812; Buffalo Gazette, March 16, 1813; Sentinel and Democrat, Burlington, VT, April 8, 1813; Vermont Republican and American Journal, Windham, July 12, 1813, and Jan. 24, 1814; The Vermont Journal, Windsor, Oct. 18, 1813; Buffalo Gazette, August 24, 1813.

[9] James B. Swain (ed.), The Life and Speeches of Henry Clay (New York: Greeley & McElrath, 1843), 105, 93. March 24, 1818.