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While serving as Upper Louisiana’s lieutenant governor between 1792 and 1799, Zenon Trudeau showed himself to be a prudent but pragmatic administrator who adopted a commonsense approach in dealing with the manifold and complex problems that confronted his administration. A Frenchman born in New Orleans on November 28, 1748, Trudeau enlisted in the Spanish army in 1769, served in the conquests of Baton Rouge in 1779 and Pensacola in 1781, and advanced to the rank of captain. He married Eulalie Delassise in 1781, and the couple had several children. Trudeau assumed command in St. Louis in July 1792. The turbulent 1790s presented him with more than his share of problems in Upper Louisiana. He had to prepare for threatened invasions by British, French, and American forces as well as for assaults from hostile Osage bands. Loyal to the Spanish government he served but realistic in the measures he advocated, Trudeau provided a steady hand at the helm in St. Louis.

Following his arrival, Trudeau sought to confront the growing British domination of the trade with Native Americans north of St. Louis. Unable to provide enough merchandise for the fur trade, the Spaniards had in effect forced many of Louisiana’s Native tribes to turn to the better-supplied British traders to the north. Upper Louisiana’s Spanish-licensed traders also had to look to foreign suppliers for merchandise. Trudeau quickly grasped that any attempts to prevent local merchants from doing business with British firms in Canada would be ruinous to commerce in St. Louis, so he chose to turn a blind eye to their illicit traffic.

However, while willing to allow St. Louis merchants to enter the northern markets, Trudeau was determined not to let British traders engage in direct trade with Native Americans in Spanish territory. In 1793 he dispatched an expedition to the Des Moines River to arrest foreign traders. Later that year he summoned all of Upper Louisiana’s traders to St. Louis to consider proposed new regulations designed to make government-controlled trading operations more equitable and efficient. When Jacques Clamorgan spearheaded the formation of a company to promote Spanish trade along the upper Missouri, Trudeau gave the venture his unqualified support. The Missouri Company was organized in 1794 and eventually sent three costly but unsuccessful trading expeditions up the Missouri. Their poor showing caused Trudeau to conclude it was unlikely that Spain could ever gain control of the trade along the upper reaches of the Missouri and Mississippi Rivers.

Closer at hand, Trudeau had to confront the continuing Osage threats to Upper Louisiana’s exposed settlements. Not long after he arrived in St. Louis, Trudeau received directives from Louisiana’s governor-general, the Baron de Carondelet, suspending all trade with the errant Osages and declaring war on them. Trudeau, who doubted the efficacy of Carondelet’s strategy, procrastinated in carrying out his orders to launch a general attack against the main Osage villages. With solid support from St. Louis traders, he continued to urge his superiors to exercise caution in dealing with the powerful Osages.

The outbreak of war between Spain and France compounded Trudeau’s problems, especially after rumors of a pending Franco-American invasion led by George Rogers Clark began circulating throughout the region in 1794. Although that threat never materialized, it persuaded Carondelet to heed Trudeau’s counsel and call off the Osage war. That decision cleared the way for a new approach to the Osage problem. With Trudeau’s backing, St. Louis fur merchant Auguste Chouteau renewed his offer to assist the Spaniards in bringing the Osages under control by constructing a fort adjacent to the Osage River villages in return for a monopoly of the Osage trade. Carondelet accepted Chouteau’s proposal, and following the establishment of an installation in present-day Vernon County, Missouri, known as Fort Carondelet, tensions with the Osages gradually subsided, to the relief of all parties.

The resumption of warfare between Great Britain and Spain in 1796 along with continuing rumors of French intrigues in Spanish Louisiana prompted Carondelet to dispatch additional military forces to St. Louis in 1797. These imminent dangers also led to renewed Spanish efforts to encourage American settlement in Upper Louisiana. Trudeau favored American immigration and was instrumental in persuading members of the legendary Daniel Boone family to leave Kentucky and take up residence in present­day Missouri along the Femme Osage Creek. During his final days in St. Louis, Trudeau allegedly signed numerous blank land-concession forms that were distributed after his departure and filled in illegally by those who secured them.

When Trudeau completed his term as lieutenant governor in 1799, the Spanish government offered him a pension, which he declined. He returned to lower Louisiana and continued in Spanish service until 1803 when Spain relinquished its control of the province. Trudeau remained in Louisiana until his death a few years later in St. Charles Parish.

Further Reading

Cleary, Patricia. The World, the Flesh, and the Devil: A History of Colonial St. Louis. Columbia: University of Missouri Press, 2011.

Din, Gilbert C., and Abraham P. Nasatir. The Imperial Osages: Spanish-Indian Diplomacy in the Mississippi Valley. Norman: University of Oklahoma Press, 1983.

Nasatir, Abraham P. Before Lewis and Clark: Documents Illustrating the History of the Missouri, 1785-1804. 2 vols. 1952. Reprint, Lincoln: University of Nebraska Press, 1990.

———. Spanish War Vessels on the Mississippi. New Haven, CT: Yale University Press, 1968.

Published February 11, 2022

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