The most notorious cases of federal military intervention in labor disputes came during America’s Gilded Age, when workers engaged in thousands of strikes across a wide range of industries. But the first instance of federal troops being called out to quash labor unrest came decades before the Civil War, from a president who does not typically leap to mind as a chief executive who sided with the forces of capital. When canal workers in Maryland rioted in January 1834 in response to poor working conditions and concerns about wages, it was Andrew Jackson, the supposed champion of the common man, who sent federal troops to help restore order.

Chartered in 1825, the proposed Chesapeake and Ohio (C&O) Canal was envisioned as a waterway across the Allegheny Mountains to connect the Potomac and Ohio Rivers, and thus to facilitate trade between the Chesapeake Bay and the Ohio River Valley. But the project was a mess practically from its inception. Initial predictions of enormous building costs gave pause to potential investors in the private company that would oversee its construction. Landowners resisted selling property along the right-of-way, and arguments broke out over locating the eastern terminus of the canal. President John Quincy Adams kept hitting rocks at the formal groundbreaking in 1828, which spoke to the challenges the terrain would pose, and construction was then slowed significantly for four years by a legal dispute with the Baltimore and Ohio Railroad over a narrow strip of land that both projects claimed to need.

Finding the thousands of laborers needed to blast and excavate the canal route, meanwhile, proved a constant challenge. It was difficult and dangerous work digging in wet and muddy ditches for long hours and low pay, and at first, the C&O Canal Company mostly imported indentured servants from the British Isles and Germany to perform it. But injuries, outbreaks of disease, and dissatisfaction with miserable living conditions and insufficient food soon led to desertions and runaways. Then, in the late summer of 1832, a cholera epidemic swept through laborer camps near Harpers Ferry, killing dozens of workers and leading many of their panicked fellows simply to abandon the canal altogether. Work on the project stopped almost entirely for months.

Construction began again in the spring of 1833, with a workforce composed predominantly of Irish immigrants hired for wages by contractors who bid to build different sections of the canal. But labor conflicts became chronic problems, and they emerged primarily from within the ranks of canal workers seeking an outlet for their grievances and some measure of control over their working conditions. At a time when unions were of questionable legality and organizing could subject laborers to charges of criminal conspiracy, canal workers with little leverage over the contractors who paid them might turn on each other violently in fights over back wages. Raising the stakes further still were traditions carried over from Ireland in which workers organized themselves into secret societies that used threats, physical assault, and, on occasion, murder, to drive away competitors.

In January 1834, rumors began spreading along the canal route of downsizing and contractor financial difficulties, and there were actual cases of work crews being dismissed without pay. On January 16, factions of workers from different parts of Ireland began fighting near the western Maryland town of Williamsport, each hoping to drive the other away and thus retain whatever jobs remained for their fellows. The battle, which broke out between Corkonians and Fardowners, who were also known as Longfords, lasted for several days and led to numerous deaths and dozens of injuries before being halted by local militia companies.

More than thirty men were arrested, but the lull in the violence lasted only as long as the militia companies remained in place. When they left, the fighting started again. On January 24, over 700 Longfords carrying guns and clubs marched on a camp of about 300 Corkonians and routed them. The Longfords killed as many as ten men, including a group of five supposedly found shot through the head, and destroyed the shanty housing in which the Corkonians lived. The militia was called out once more, as was the county sheriff. Canal company managers and local militia leaders persuaded the laborer factions to pledge to keep the peace and not to interfere with workers on the canal, with a warning that the militia would drive any faction engaging in future hostilities out of the county.

The workers who had been arrested were released, and some measure of calm was restored. But local residents of Williamsport, terrified by the chaos surrounding them, had pleaded with the Maryland House of Delegates for protection, and the legislature responded on January 28 with resolutions calling on President Jackson to send “such portion of the Military of the General Government as in his opinion may be necessary to protect our citizens and prevent any injury to the public works and property of individuals.” Jackson responded immediately, ordering the Secretary of War the very next day to send “at least two companies of regulars” to “put down the riotous assembly.”

Troops arrived over the course of the next several days, amounting to a little less than 100 soldiers, and they remained in place, ensuring that canal work continued without incident, for nearly two months. The president of the C&O Canal Company expressed relief that the presence of federal forces would make it much easier to fire canal workers without worrying that they would riot. It was surely no coincidence that the company president was John Eaton, Andrew Jackson’s close personal friend and his former Secretary of War.

The riots of January 1834 would not be the last along the construction route of the C&O Canal. The company and contractors still sometimes withheld wages and pitted crews of laborers against each other for work, leading to sporadic unrest, violence, ethnic conflicts, and strikes in the years to come. Friction was exacerbated significantly by an economic depression that began in 1837, and sometimes the forces of the state intervened. In 1839, for example, state militia units arrested several dozen men near Little Orleans, Maryland, about forty miles from Williamsport, in response to an especially vicious assault by Irishmen on a camp of German canal workers. This time, most of the arrested were tried and sentenced to prison, in some cases for terms of nearly twenty years.

The Chesapeake and Ohio Canal would never be completed as it had been originally envisioned. Construction stopped near Cumberland, Maryland, in 1850, just sixty miles or so west of the site of the 1834 riots, and more than 100 miles short of the canal’s planned route. Struggles between labor and capital on industrial infrastructure projects in the United States, however, had only just begun. And the precedent set by Andrew Jackson of bringing federal military might to bear on one side of those struggles would be followed by future presidents, some of whom made not even the pretense of supporting workers that he did.