A plot to invade Mexico – Tim Fanning on the trials of James Workman and Lewis Kerr

An Irishman’s Diary

In 1807, two Irish lawyers went on trial in New Orleans. It was alleged that the accused, James Workman and Lewis Kerr, had plotted to send a force to invade Mexico and to seize the city's banks in order to fund the expedition.

Both men were members of the Mexican Association, a secret society committed to wresting Mexico from Spanish rule.

The trials – the jury in the first trial was discharged, having failed to reach agreement – were linked to the former US vice-president Aaron Burr's plans to establish his own independent nation to the west of the United States: the so-called Burr Conspiracy.

The involvement of the Mexican Association, a group of merchants and professionals based in New Orleans, had a distinctly Irish flavour.


A merchant from Co Sligo, Daniel Clark, had founded the society in the early 1800s. Its original purpose had been to police New Orleans in the wake of the Louisiana Purchase by the United States. Workman was invited to join the Mexican Association in 1804 after his appointment as a judge in the city. Shortly afterwards, he was elected the society's president.

From Cavan town, Workman had studied law at the Middle Temple in London before emigrating to the United States in about 1800. Before arriving in New Orleans, he had worked as a journalist and critic in Charleston, South Carolina, where he had written a play, Liberty in Louisiana, which celebrated the end of Spanish rule in the territory.

By shipping off tens of thousands of Irish rebels to South America, the British government would remove the threat of sedition from Ireland

But it was Workman’s political ideas that brought him to the attention of the Mexican Association.

Before arriving in the United States, Workman had advocated a detailed plan for the British invasion of Spanish America by Irish veterans of the 1798 rebellion.

It called for an initial invasion force of 8,000 troops to take Florida and Louisiana. A further 22,000 soldiers would then set sail from Ireland bound for Buenos Aires. After taking the city, the troops would make their way up the rivers Paraná and Uruguay, taking control of northern Argentina and Uruguay. With 16,000 men left behind to hold these territories, the remaining 6,000 would sail around Cape Horn to invade Chile.

Reinforcements from Ireland aided by the Irish garrison in Chile would then take Peru, with British troops based in India sailing across the Pacific to raid the coasts of Mexico, Central America and the northern part of South America.

Aside from adding a vast chunk of the world’s landmass to the British Empire, Workman saw an added benefit to his improbable plan. By shipping off tens of thousands of Irish rebels to South America, the British government would remove the threat of sedition from Ireland.

Those who volunteered for the army would be entitled to grants of land in the conquered territories and supplied with “instruments of agriculture, and other reasonable assistance”.

Because most would be Catholic, Workman believed the Irish soldiers would be opposed with “less fury and acrimony” in Spanish America than “any others of his Majesty’s subjects”. The plan would not only “completely restore tranquillity to Ireland” in the aftermath of the 1798 rebellion but “render that country the strongest arm of the British Empire”.

Workman and Kerr were arrested. Both were acquitted of all charges but their legal careers inevitably suffered

While Workman's plan did not receive a favourable hearing, it became one of a number of invasion proposals put forward during this period that gave impetus to the British invasions of Buenos Aires and Montevideo in 1806 and 1807.

Once in the United States, Workman continued trying to interest politicians in his political ideas. In 1801, he wrote to President Thomas Jefferson, advocating that the United States take control of Florida and Louisiana from the Spanish and abolish slavery in the territories.

In New Orleans, Workman and the Mexican Association's plans for revolution became entangled with those of Aaron Burr. While the details remain contested, it's probable that Burr and his co-conspirators aimed to establish an independent country centred along the Mississippi and Ohio valleys and extending into Spanish territory in Texas and Mexico.

When one of the plotters, Gen James Wilkinson, decided to rumble the plot to save his own skin, Workman and Kerr were arrested. Both were acquitted of all charges but their legal careers inevitably suffered. Kerr chose to leave New Orleans, settling in the Bahamas, where he became solicitor-general and a speaker of the House of Assembly.

As for Workman, he was expelled from the bar after the trial but remained in Louisiana and was gradually rehabilitated. Proving that even the most ardent revolutionaries all too often become conservatives, by the time of his death in a boating accident in 1832, he was described in the Louisiana Advertiser as “one of our most worthy and ancient citizens”.