In the footsteps of… a 19th-century revolutionary campaign across the Andes
In 1817, Argentine general José de San Martín launched an epic expedition to liberate Chile and Peru from Spanish rule. Laurence Blair traces the high-altitude journey of his army and its forgotten black soldiers
Originally published in issue 10 of BBC World Histories Magazine, June 2018.
In January 1817, a band of soldiers entirely unused to the cold, breathless conditions of the Andes tramped over lofty passes from western Argentina into Chile. Not only had they little or no experience of the effects of altitude, around half were not of American or European descent, but African. Yet these men, fighting under an ailing general with an audacious plan, achieved victories that swung the balance in favour of the independence of Argentina, Chile, Peru and beyond.
In the mid-1810s, the future of an independent Latin America was poised on a knife-edge. Spanish royalists had quashed patriot risings across the region. The fractious, penniless United Provinces of the Río de la Plata — roughly speaking, covering what is now Argentina and Uruguay plus parts of southern Bolivia and Brazil — headed by Buenos Aires, barely held the Spanish at bay in Upper Peru.
Into the picture stepped José de San Martín, a middle-aged, austere and iron-willed career soldier, now a general of the province’s army, with an audacious strategy: to march west over the Andes into Chile, surprising and crushing royalist forces there, then sail for Lima to liberate Peru. By capturing “the fortress of tyranny,” they would decapitate Spain’s American empire.
From 1814, San Martín transformed Cuyo province (now in far western Argentina) and its capital, Mendoza, into a total war economy — improving irrigation and farming, building arms factories, setting women to work stitching uniforms, unleashing spies and guerrillas into the mountains. As for manpower, “There is no alternative,” he wrote to a friend. “We can survive only by putting every slave under arms.”
Freedmen, runaways and conscripts — many drawn from the 70,000 slaves brought to the Río de la Plata between 1777 and 1812 — had previously formed black battalions, which served with distinction in the early 1810s. But San Martín extended slave recruitment massively, and roughly half of the 5,000-strong army that he had assembled by 1817 were black or mixed-race, with many born in west Africa, according to historian Peter Blanchard. They were promised freedom after six years’ service, but some felt similarly patriotic to one Antonio Castro, who asked to join the black Eighth Regiment in 1815 “to sacrifice himself for the just case of his patria”.
Their ranks were swelled by British and Irish officers and several hundred exiled Chileans, including Bernardo O’Higgins, who would later become Supreme Director of post-independence Chile. San Martín also secured the tacit support of the indigenous Pehuenche people who controlled the nearby passes.
Into the Andes
In January 1817, four small detachments departed — two far to the north, two to the south — to draw royalist forces away from Santiago in Chile. Finally, staggered between 18 and 25 January, San Martín’s main force of 3,200 men, 9,251 mules, 1600 horses and 600 cows set out from their camp, El Plumerillo — an ad hoc city of canvas and wood on the outskirts of Mendoza. They marched and rode amid rolling fields of pasture under a hot summer sun, dividing at El Jagüel. Here, a column of 800 men under brigadier Juan Gregorio de las Heras split off and headed for the Uspallata pass (also called La Cumbre), escorting the artillery and heavy baggage. They crossed what Charles Darwin, passing through in 1835, would call a “long and most sterile” stretch of 30 miles, with swathes of bare soil alternating with “numberless dwarf cacti, armed with formidable spines”. They entered the heart of the mountain range via the Puente del Inca, an imposing natural rock arch, and battled with small royalist detachments for control of the passes at Picheuta (24 January), Potrerillos (29 January) and Guardia Vieja (4 February).
These were bloody melees that stand out in Las Heras’s otherwise matter-of-fact letters. Passing the aftermath of the Potrerillos skirmish, he noted dead enemy officers, bullet-holed clothing and supplies strewn about the mountainside, “the enemy position awash with traces of blood”. At Guardia Vieja, he recorded — somewhat bemusedly — how an enthusiastic Dominican chaplain had begged to join the attacking guerrillas and “having fired his rifle, charged with his sabre upon the fleeing enemy and made one of their officers prisoner”.
The main force under San Martín faced an even harder crossing, via Paso Los Patos —in reality, a series of passes some 40 miles farther north. Ascending from the plains into the first of four mountain ranges on 21 January, a fierce hailstorm forced the army to halt and spend a freezing night in the open, at Valle Hermoso.
Emerging from a trench in the morning, San Martín called for brandy, lit a cigarette, and ordered the trumpeters to strike up the national anthem. Despite this show of sang-froid, his private letters betrayed his fears. “What keeps me awake is not the resistance of the enemy,” he wrote, “but the crossing of these enormous mountains.”
Trudging deeper into the cordillera, the army — forbidden from lighting large fires, smoking or talking while marching — was swallowed up by towering, jagged ranges of Cenozoic rock. They passed white fossils of ammonites speckling the scree of the Piuquenes range, a former seabed 200 million years old. At an altitude of about 2,000 metres, they perhaps observed the same “coarsely crystallized white calcareous spar” — the petrified remains of Triassic trees, covered by “enormous streams of submarine lava” — that astounded Darwin.
As they approached the highest point of their journey at the Espinacito pass (4,536 metres) on 27 January, climatic extremes became more pronounced: temperatures plummeted from 30°C during the day to –10°C at night, chilling the men through their uniforms, ponchos and blankets. Few of the soldiers would have previously experienced altitudes over 3,500 metres, or endured such cold and exposure for so long. “At nightfall I feared my troops in peril from the intense cold,” O’Higgins wrote on 1 February, trapped on an exposed ridge with the black Eighth Regiment, a howling wind whipping around them. An estimated 300 men died during the crossing, from exposure, injury and in combat.
Walking the high passes in the austral summer, the dryness of the air, the fierce sun and the dust of the trail combine to burn and dry out exposed skin, resulting in nosebleeds and scabbed lips. The fording of freezing rivers, swollen by the summer snowmelt, probably provided little relief. Altitude sickness, too, was an unnerving sensation. Darwin recorded how his Chilean guides had “the most ridiculous notions” concerning the so-called puna. They linked it to the presence of snow and water as a kind of malignant disease; graves dotted the trail where those who had supposedly died punado were buried.
Sustaining San Martín’s soldiers through all of this was a rudimentary diet of tough charqui (beef jerky), maize biscuits softened by animal fat, rum, and a bottle of wine per day. They chewed raw onions and garlic to ward off the puna. Despite the soaring outcrops of igneous rock that surrounded them, tinted in hues from iridescent lilac to dark maroon, their immediate environs were dispiriting. Less than half of the beasts of burden arrived in Chile. Drovers were forced to walk their mules along the very edge of the precipitous paths to avoid the cargoes they carried bouncing off the cliff-face and toppling both beast and burden into the void. Even so, the sides of the path were littered with dying, broken-limbed pack animals, the valleys echoing with their cries.
Given the purgatory of the crossing, it would have been with huge relief that the army crossed Las Llaretas pass into Chile on 2 February, the harsh talus of the mountains soon giving way to verdant meadows strewn with wild flowers. The advance guard charged unsuspecting royalist detachments, winning victories at Achupallas (4 February) and Las Coimas (7 February). Hot on the heels of fleeing royalists, San Martín’s forces crossed the Aconcagua river and reunited with Las Heras’s column on 9 February.
The 21-day Andean crossing, San Martín wrote, “has been a triumph”, but the serious fighting still lay ahead. Some 2,500 royalists were amassed nearby, at the Chacabuco estate on a hilltop north- west of Santiago. After two days of reconnaissance, at daybreak on 12 February San Martín ordered the advance. An impetuous O’Higgins hurled himself at the enemy with his black regiments, taking heavy losses. Only a last-minute charge by the commander- in-chief at the head of his mounted grenadiers, and the eventual arrival of a flanking movement, saved the day. The Spanish lost 600 men and hundreds of prisoners; the patriots suffered casualties of 12 dead and 120 seriously wounded.
A lavish victory ball was thrown in Santiago — guests smashed their glasses on the floor in a toast as black trumpeters played the anthem — and on 12 February 1818, the first anniversary of the battle of Chacabuco, Chile’s independence was declared. Yet it took a further bloodbath on 5 April at Maipú, just south-west of Santiago, to secure central Chile. During that clash a crack Spanish regiment inflicted serious casualties among the infantry, yet “nothing could exceed the savage fury of the Black soldiers,” wrote a British observer, Samuel Haigh. “They had lost the principal part of their forces; they were delighted with the idea of shooting their prisoners.”
This zeal was understandable. Before setting out from Mendoza, San Martín had shown them what he claimed were intercepted royalist orders that captured black soldiers be returned to slavery in Peru’s sugar plantations. Decades later, when an “old African” who had fought at Chacabuco was interviewed, he “pulled from his pocket a paper in which he kept the moustache of a Talavera [a member of that royalist regiment]”. The veteran explained how he had cut down the Spaniard with his bayonet, shot him, and “cut off his moustache with the lip and everything”, shouting (translated roughly) “Here’s your sugar!”
San Martín’s forces went on to win further victories in Peru. But the 1817–18 campaign marked the highpoint of the Argentine liberator’s career — a rare moment of trans-national unity in a region that soon fell into anarchy and division, and the point at which the struggle for independence swung decisively in the patriots’ favour.
San Martín’s vision, and the bravery of his black regiments — the backbone of the so-called Army of the Andes — have faded from popular memory, especially outside Argentina. But as migration to Chile from Colombia, Venezuela and the Caribbean challenges the country’s idea of itself as predominantly white, the multiracial history of the region’s independence struggle is once again being told.
Contemporaries had few doubts that victory was, in large part, owed to the slaves and freedmen who fought under the flags of freedom. They “deserve the highest praise for their constancy and valour,” wrote William Miller, one of San Martín’s officers. In marching, fighting and dying, they helped pave the way for the freedom of a continent — and, in time, that of their own people.
José de San Martín: soldier, politician, reluctant hero
José Francisco de San Martín y Matorras (1778–1850) was born in Yapeyú, near the modern-day Argentina-Brazil border, but at the age of seven moved with his Spanish parents to Málaga. He joined the Spanish army when he was 11, serving in north Africa, the Mediterranean and the Peninsular War. Despite rapid promotion for his bravery and discipline, he became disillusioned with Spanish rule.
A visit to London exposed him to a circle of Latin American revolutionaries, though he remained a lifelong conservative and monarchist. Returning to Buenos Aires in 1812, San Martín proved an effective defender of the nascent United Provinces of the Río de la Plata. Appointed governor of Cuyo in 1814, San Martín used the province as the launchpad for a daring trans-Andean invasion of royalist-controlled Chile, winning decisive victories at Chacabuco (1817) and Maipú (1818).
There followed a seaborne invasion of Lima (1820), the stronghold of Spanish rule in South America. But at a secret conference in Guayaquil in 1822, the erstwhile Protector of Peru ceded his forces to Simón Bolívar, who defeated the Spanish at Ayacucho (1824).
Rather than be dragged into civil war in Argentina, San Martín went into exile in Europe, dying in Boulogne-sur-Mer in 1850 “in a sequence of pain and opium”, in the words of his biographer, John Lynch. His remains were reinterred in the cathedral of Buenos Aires in 1880.