Innovative technologies have always offered an avenue of employment for American soldiers of fortune. They honed the skills required in order to use these cutting-edge technologies while serving in the American armed forces. Examples of these technologies include observation balloons, torpedoes, submarines, dynamite, nitroglycerin and the airplane. All were seen as potentially the great equalizers, the weapons that could empower the underdogs in their struggles against their more powerful enemies. Frequently, the employers of these American soldiers of fortune were American arms merchants who were hired by some foreign underdog to mitigate the strength of the more powerful.One has good reason to be skeptical that the observation balloon could change the course of a war, particularly following its indecisive debut during the U.S. Civil War. Yet this was exactly what happened in the War of the Triple Alliance (1864–70) between Paraguay and Brazil (supported by Argentina and Uruguay). Do not relegate this conflict to “just another banana war.” The war lasted almost six years, and Paraguay alone suffered about 150,000 casualties—half its population.Aerial ObservationAmerican balloonists Ezra and James Allen were hired by the Brazilian government to reconnoiter a strong Paraguayan defensive position from the air. The Allen brothers learned their trade while serving in the Union Army. The brothers traveled to Brazil, taking along their balloon and inflation equipment. Intelligence gleaned from the American-operated observation balloon permitted the Brazilian Army to bypass the Paraguayan defenses known as the Lines of Rojas. These defenses had brought the Brazilian advance to a halt and prevented the Brazilians from forcing the Paraguayans into a decisive engagement. The reward for the Allen brothers was the proof of the success of their balloon operations during the war. Emperor Dom Pedro II presented the brothers with a bonus of $10,000 in gold. Rarely were American soldiers of fortune paid well for their services, in spite of promises. This was one of the exceptions.Perhaps no weapon offered greater hope to the underdog than the torpedo, particularly when the enemy controlled the seas. In the mid-1860s, former Confederates were the most experienced in the development and application of this new weapon. A number of these individuals had served in the American Army prior to the Civil War. In the late 1870s, the Peruvian government hired American arms merchant Charles Flint to eliminate Chile’s sea power advantage during the War of the Pacific. Flint purchased torpedoes and torpedo boats. He hired former Confederate Charles Read to sink the backbone of the Chilean Navy, the Almirante Cochrane and Blanco Encalada. The torpedo boats, torpedoes and Read all successfully entered Peru through the Chilean blockade. The attack on the Chilean warships was never carried out because of bickering among Peruvian naval officers, and Read and the entire effort went for naught.In the 1880s, Irish-Americans perceived dynamite and nitroglycerin as being the most promising weapons to help them free the Emerald Isle from British rule. Although these explosives were their first weapons of choice, the submarine briefly caught their fancy. An Irish-born inventor, John Holland, demonstrated enough promise that the Irish-Americans invested in his research and the construction of his submarine, the Fenian Ram. Holland’s association with his benefactors was short-lived on account of a falling out. The construction of a submarine proved too complex, time-consuming, difficult to hide and expensive for these Irish-American soldiers of fortune—hardly the ideal weapon for the underdog.Those other new weapons, however—dynamite and nitroglycerin—offered immediate promise. The Irish-American revolutionaries, a number of whom had served in the Union Army, conceived a new strategy to employ these powerful explosives. The goal became terror, and the strategy became the bombing of British cities—London in particular. Operating from the U.S., the bombers would cross the Atlantic, explode their devices and then retreat to the safety of America. Between 1881 and 1885, the Irish-American bombers carried out a number of attacks, even damaging some of London’s best-known landmarks—the Tower of London and the Parliament building.New Technologies, New TacticsInnovative technologies employed by American soldiers of fortune were the backbone of the Brazilian government’s attempt to defeat its mutinous navy during an 1893–94 revolution. Brazilian President Gen. Floriano Peixoto pursued a variety of paths to defeat Adm. Custódio José de Mello. He offered American mercenary George Boynton Stone $600,000 in gold to sink the flagship of the rebellious navy, the q. Stone’s plan was to tow a non-self-propelled torpedo into the path of the rebellious flagship. His towing vessel was a harbor tug, upon which he chose to fly the British flag for protection. The British took offense at the misuse of their flag and took Stone into custody. Turned over to the U.S. Navy, he was shipped home under confinement.At the same time as the Stone endeavor, the Brazilian government turned to Flint. His job was to defeat the Brazilian Navy by whatever means he could purchase. He approached his task with gusto. He bought every high-tech weapon he could get his hands on—notably, the torpedo boat and the dynamite gun. It mattered not to Flint that these weapons had not proven themselves. He wanted them as much for their publicity value as their military prowess. Much heralded, the dynamite gun launched a dynamite charge by compressed air at opposing forces. The few times the weapon was fired demonstrated how difficult it was to hit a moving target. This mattered little to Flint. Christened the Dynamite Fleet, Flint’s mercenary navy, manned mostly by Americans, arrived off the coast of Brazil as the Brazilian Navy was collapsing due to the lack of local support. The Dynamite Fleet played no part in the conflict but received much press.* * *These examples of American soldiers of fortune employing innovative technologies in the service of foreign lands are but a few of the known cases. We estimate that some 10,000 Americans chose to be soldiers of fortune or mercenaries during two centuries. We can identify about 1,000 by name. Of these 10,000 Americans, we estimate that a third to half had learned their skills while serving in the American armed forces.