The United States became an imperial power almost by accident. On Feb. 15, 1898, the armored cruiser USS Maine exploded in Havana Harbor. A month later, following an official investigation into the matter, a Navy board of inquiry concluded a mine had sunk the vessel, thus implicating Spain, Cuba’s overlord. On the heels of that decision the United States declared war on one of Europe’s oldest empires. In the Spanish-American War, naval supremacy was to prove decisive.

In Banana Wars naval historian Ivan Musicant asserts, “The American naval renaissance and the rise of the United States as an empire and world arbiter were parallel and symbiotic.” Unlike the U.S. Army, which bumbled into the conflict with poor logistics, outdated rifles and tins upon tins of contaminated meat, the Navy, with its augmented fleet of cruisers, revenue cutters, gunboats, armed tugs and yachts, supply and repair vessels and colliers, successfully routed a Spanish fleet that had seen better days. The Navy’s crowning achievement occurred on May 1, when Commodore George Dewey’s Asiatic Squadron took Manila Bay in a single day. Soon thereafter prominent citizens in New York and San Francisco erected the Dewey Arch in Madison Square and Dewey Monument in Union Square, respectively, as symbols of U.S. naval might.

Imbued with confidence and a fleet that could stand up to a first-class European navy, President Theodore Roosevelt, among the great cheerleaders of American imperialism, added the Roosevelt Corollary to the Monroe Doctrine, warning European nations to refrain from future interference in Latin American affairs. “Chronic wrongdoing, or an impotence that results in a general loosening of the ties of civilized society,” he proclaimed in a 1904 address to Congress, “may force the United States, however reluctantly…to the exercise of an international police power.” From then until the 1930s—when President Herbert Hoover issued the Clark Memorandum, stepping away from interventionism, and another president named Roosevelt enacted the Good Neighbor policy, calling for political and economic détente with Latin America—the United States was the undisputed master of the Western Hemisphere.

America’s hemispheric influence saw its apogee in the 1920s. Although the Roaring Twenties are often seen as an age of isolationism, the truth is the Navy and Marines were quite active in Haiti, Honduras and the Dominican Republic. But no state saw more American boots on the ground than Nicaragua.

America’s troubled relationship with Nicaragua has its origins in 1854, when a civil war broke out and pitted two political factions against each other. The liberal Democratic Party, centered in the city of León, feared that the conservative Legitimist Party, based in Granada, would soon take full control of Nicaraguan politics. The liberals, headed by Francisco Castellón, contracted the services of an American filibuster (or military adventurer) from Tennessee. That filibuster was none other than William Walker, an enigmatic warlord who in 1853 had very nearly succeeded in turning Baja California into his own private fiefdom. Before sailing for Nicaragua from San Francisco, Walker promised his recruits up to $30 a month and a bonus of 250 acres of public land after six months’ service. Fifty-seven American and foreign mercenaries signed up, and between 1855 and ’56 Walker’s American Phalanx defeated the Legitimist forces in several small battles.

On July 12, 1856, Walker had himself inaugurated as the president of Nicaragua, and remarkably enough U.S. President Franklin Pierce recognized his government. To rub salt into the wounds, Walker staged his inauguration in the conservative capital of Granada.

Walker’s tenure as the most powerful man in Nicaragua did not last long. The gray-eyed filibuster—considered a social democrat by such European intellectuals as Swiss engineer Arnold Bürkli—was ultimately defeated by a coalition of Central American states during the campaigns of 1856–57. Walker managed to save his skin for a few years by surrendering to a U.S. Navy commander, but on his unwelcome return to Honduras’ Bay Islands in 1860, British naval authorities took Walker into custody and promptly handed him over to Honduran authorities. On Sept. 12, 1860, a Honduran firing squad executed the 36-year-old man who would be king.

Decades later the legacy of Walker still burned in the hearts and minds of many Nicaraguans. Similarly, the bad blood between liberals and conservatives did not dissipate after Walker’s death, and indeed the rivalry flared up again in 1926. Following a U.S.-supervised election in 1924, Emiliano Chamorro Vargas—who had been the country’s president from 1917 until 1921—led his ultra-conservative partisans in a successful coup, seizing Loma Fortress in the capital of Managua, forcing the resignation of President Carlos José Solórzano and booting all liberals from Congress. As yet another civil war broke out and liberal rebels attacked the Caribbean coastal city of Bluefields, the U.S. Navy steamed south with a contingent of Marines assigned to protect American lives and property. They made landfall on Jan. 24, 1927. Mexico, or more correctly the left-wing Mexican Revolution, which the administration of President Calvin Coolidge feared might be exported to Nicaragua, provided further impetus for the intervention. That spring Coolidge sent statesman-soldier Henry L. Stimson to broker a peace deal that called for a U.S.-sponsored presidential election in 1928. Conservatives and liberals alike were called on to hand over their weapons to the Marines. All consented, except for one liberal revolutionary—Augusto César Sandino.

The illegitimate son of a Spanish landowner and an indigenous servant girl, Sandino was homeschooled and then spent several years as an itinerant worker. Following a bloody dust-up with the son of a prominent conservative politico, the 26-year-old firebrand fled to Tampico, Mexico. While there, between shifts at the Standard Oil refinery, Sandino imbibed the heady brew of revolution, taking inspiration from the anti-imperialism and anticlericalism of Mexican communists, the anarchism of American labor unionists and Indo-Hispanic nationalism. Sandino was both a mystic and a revolutionary, and his one-man war against the Marines captivated anti-American audiences in the republics of Central and South America.

Initially, U.S. officials in Nicaragua considered Sandino and his men mere bandits. Reports from 1927 and 1928 consistently estimate his “army” scarcely numbered more than 100 men, with its area of operation confined to the northern border with Honduras. Military authorities believed Nicaragua’s small national guard, an apolitical constabulary led by Marine officers and noncommissioned officers, could adequately deal with the threat.

Sandino shattered that illusion at the Battle of Ocotal on July 16, 1927. The clash broke out at 1:15 a.m., when one of the 37 Marines stationed in town noticed shadowy bands of men gathering outside a church near the plaza. The Sandinistas, numbering upward of 400 men, began the attack by screaming “Viva Sandino!” and throwing bombs at the Americans. The guerrillas got close to City Hall—where the Marines and nearly 50 national guard soldiers were garrisoned—before steady machine gun, rifle and rifle grenade fire forced them back. As the fighting dragged on into the daylight hours, the outnumbered Marines seemed fated to a long siege. But patrolling Marine aviators flying five De Haviland DH.4 biplanes had gotten wind of the disturbance. Shortly before 3 p.m. they began dive-bombing the Sandinistas, who scattered in panic. By 5 p.m. only a few enemy snipers remained to be cleaned up. In fending off the frontal assault, the Marines and national guardsmen had cut down as many as 100 rebels for the loss of one killed and a handful wounded.

Following their fiasco at Ocotal the Sandinistas never again dared face the Marines in open combat. Instead, their war devolved into a guerrilla insurgency, with the rebels ambushing small bands of Marines and guardsmen that were patrolling the jungles and mountains of Nicaragua’s interior. Such warfare benefitted Sandino and his men, many of whom were part-time soldiers, paid a few dollars a day to wield machetes. Hoping for a knockout blow that fall, the Marines sent a large force against El Chipote, Sandino’s mountain headquarters near the Honduran border in the Nuevo Segovia department. Between September and October a mixed force of Marines and national guardsmen mounted an offensive against some 250 Sandinistas holed up in and around El Chipote. Marine aviators flew reconnaissance and close air support missions to provide overwatch for the ground troops. The American-led force ultimately managed to capture El Chipote, though by then Sandino and most of his men had vanished into the jungle.

Despite losing on the ground, Sandino scored several propaganda victories during the El Chipote offensive. One came when Marine 2nd Lt. Earl A. Thomas was forced to crash-land his DH.4 after the aircraft was struck and disabled by Sandinista ground fire. Thomas and observer Sgt. Frank E. Dowdell were killed on the ground during a firefight with rebels, who sent to newspapers in Honduras and Mexico a gruesome photograph of Thomas’ body hanging from a tree.

Frustrated Marine officers realized putting down the Sandino affair would require some creativity. Among the more successful initiatives revolved around future Marine Corps legend Merritt A. “Red Mike” Edson. In early 1928, resolving to deny Sandino control of the strategically significant Coco River, the red-bearded captain and his 160-man Marine detachment linked up with the coastal Miskito people. Leveraging the traditional animosity between the Spanish-speaking Ladinos of the interior and the Anglophile mixed-race Miskitos, Edson’s Marine patrols used Miskito guides and boats to penetrate deep into pro-Sandino territory. In response the Sandinistas raided coffee plantations and stores owned by Americans and Europeans while threatening violent reprisals and/or death to any local with pro-American sympathies. Among the rebels’ favored execution methods were the corte de cumbo (top hat cut), in which a victim tied to a tree had the top of his skull hacked open by a machete, and the corte de blumers (bloomers cut), in which a victim had his legs cut off at the knees, followed by his hands, and was left to bleed to death.

While Edson’s Rio Coco patrol proved successful in keeping the rebels on the run and even seizing the Sandinista stronghold of Poteca and killing one of Sandino’s chief officers, the unit was nevertheless disbanded in 1929. The incoming Hoover administration wanted a clean end to the mess in Nicaragua and, in the wake of the largely peaceful elections of 1928, had promised the new government a withdrawal of most of the Marines by year’s end 1930.

The other major military innovation came courtesy Marine Col. Douglas McDougal. In March 1929, recognizing Washington wanted the Nicaraguan national guard to take over offensive operations during the phaseout of the Marines, the newly arrived McDougal created the 1st Mobile Battalion. Initially comprising 200 national guard troops led by 14 Marine officers, the battalion was split into several mobile columns dedicated to harassing Sandinistas up north. That summer McDougal selected 60 men for an elite mobile column under the command of Capt. Herman Hanneken, a legendary Marine who’d received the Medal of Honor for killing Haitian guerrilla leader Charlemagne Péralte in 1919. Redesignated Company M, it became the most feared mobile column of the American intervention. Soon leading it in the field was another future Marine legend, Lt. Lewis “Chesty” Puller, himself a veteran of the occupation of Haiti.

Company M took the battle to Sandino in and around Jinotega, capital of the namesake department and the most strategically important city in north-central Nicaragua. Spending some 20 days of every month in the field, Puller’s men conducted long-range reconnaissance patrols that averaged 30 miles a day and required them to live off of the land. Unlike other Marine officers, the bullish young lieutenant had the complete trust and loyalty of the Nicaraguan soldiers beneath him. His fearlessness in combat earned Puller the nickname “Tiger of the Mountains.”

But even his success in the field could not stem the steady stream of Marines leaving Nicaragua. By the summer of 1930 Company M had been reduced to just two Marine officers (Puller and Lt. William Lee) and fewer than three dozen national guardsmen. Sandino’s rebellion remained active and was still claiming American and Nicaraguan lives. Indeed, that New Year’s Eve a force of 100 Sandinistas ambushed a 10-man Marine patrol northeast of Ocotal, killing eight and wounding two. Ratcheting up the tension was the looming 1932 presidential election, a process somehow to be guaranteed by a Marine force numbering less than 1,000 men.

The last scrape of the war in Nicaragua came in that election year. In late December outgoing liberal president José María Moncada (Sandino’s former commanding officer) sought to extend hope to his troubled nation by driving a golden spike to mark completion of a railroad linking León and El Sauce. Word spread Sandino aimed to disrupt the ceremony with a full-scale battle, so Puller, Lee and a half-dozen other Marine officers gathered 64 national guardsmen and boarded a train for El Sauce. Their goal was to disrupt Sandino’s planned disruption.

The day after Christmas the train carrying Company M came upon a band of some 250 Sandinistas looting the railroad commissary outside El Sauce. The fight erupted as rebels on both sides of the tracks opened up on the train, forcing Puller and his men from their carriages. Half the guardsmen formed up on the right under Puller, the other half on the left under Lee. From the shelter of a dry creek bed Lee’s men pinned down the Sandinistas, while Puller’s team sought to turn the enemy’s flank. The decisive moment came when Cpl. Bennie M. Bunn charged the Sandinista left with his Browning automatic rifle, laying down accurate fire and prompting a general rout. The Battle of El Sauce lasted barely an hour. The Sandinistas left behind 31 corpses along the tracks and likely dragged off other casualties, while the national guard lost three dead and three wounded. In gratitude President Moncada promoted Puller to major and Lee to captain in the guard. Regardless, both officers, as well as the remaining Marines, left Nicaragua for good in January 1933.

By 1933 neither the Marines nor Sandino had managed to end the civil war in Nicaragua. A pro-American government ruled Managua, but Sandino controlled the interior and large swaths of the Atlantic coast. The country was at a stalemate. So that February, a month after the U.S. pullout, Sandino traveled to Managua to discuss a cease-fire with President Juan Bautista Sacasa.

On the other side of the negotiating table beside Sacasa was national guard commander Anatasio Somoza, who listened in silence as Sandino denounced the guard as a criminal institution and argued for its disbandment. Somoza did not forget the insult. When Sacasa and Sandino met again in Managua a year later, Somoza sprang a trap. Around 10 p.m. on Feb. 21, 1934, as Sandino, his brother and two Sandinista generals left the presidential palace, national guardsmen stopped their car, dragged them off to a nearby military airfield and executed them. Sandino’s body was never found. A day later guardsmen overran the main Sandinista camp up north, killing or disarming the remaining rebels over the following weeks. In 1936 Somoza overthrew Sacasa and assumed the presidency. He ruled Nicaragua as a dictator, largely uninterrupted, until his own assassination in 1956.

Augusto Sandino remains a hero to the left in Latin America. In Nicaragua he is the enduring symbol of resistance to U.S. interventionism, thus it is no surprise the largest left-wing party in Nicaragua is known as the Sandinista National Liberation Front. As for the Americans and the fighting Marines, their bloody 1927–33 intervention is hardly remembered at all.

Benjamin Welton is a Boston-based history doctoral candidate and freelance writer. For further reading he recommends The Sandino Affair, by Neill Macaulay; The Banana Wars, by Ivan Musicant; The Savage Wars of Peace, by Max Boot; and Chesty: The Story of Lieutenant General Lewis B. Puller, by Col. Jon T. Hoffman.