Luis de Moscoso Alvarado was a member of Hernando De Soto's expedition to explore La Florida-today's southeastern United States-and to obtain gold and other riches from the native peoples of the North American continent. The army of an estimated 600 men sighted land on May 25, 1539, on the western coast of Florida near what is now Tampa Bay, and landed on May 30. Over the next four years the expedition traveled throughout the southeastern United States. On May 21, 1542, De Soto died from a fever at the Mississippi River in what is now Arkansas; command of the expedition was transferred to Moscoso. The remainder of the journey is commonly known as the Moscoso expedition. The primary goal of its surviving members was to find an overland route back to New Spain (now Mexico). Many attempts have been made to reconstruct the route of the expedition, nearly all of which bring it into Texas in the summer of 1542.
Scholars have attempted to trace the Moscoso expedition route through Texas mainly with information found in four primary accounts of the journey. A brief version of the army's exploits in La Florida is found in a narrative by the King's factor, Luys Hernández de Biedma, who accompanied Moscoso. This account was written eleven years after the expedition, while Biedma was living in Mexico. Another account is the True Relation of the Hardships Suffered by Governor Fernando de Soto and Certain Portuguese Gentlemen During the Discovery of the Province of Florida. Now Newly Set Forth by a Gentleman of Elvas. This work first appeared in 1557-just fourteen years after the expedition-and was produced anonymously by a Portuguese member of the expedition. A third written source is a romanticized account of the expedition by Garcilaso de la Vega, entitled A History of the Adelantado Hernando de Soto. Garcilaso was not a member of the expedition, and his account was written in the latter part of the sixteenth century and published in 1605. It was based on at least two written and one oral account by expedition members. A fourth account was published in 1851 in Gonzalo Fernández de Oviedo's Historia general y natural de las Indias. This account was by De Soto's private secretary, Rodrigo Ranjel.
The most exhaustive early attempt to reconstruct the route of the Moscoso expedition, not only in Texas but through the entire southeastern United States, was published in 1939 by the United States De Soto Commission to celebrate the expedition's 400th anniversary. The commission's proposed version of the route through Texas posits that the expedition, led by Moscoso, entered Texas in what is now Shelby County and from there traveled south to a point near San Augustine. It then turned west and went as far as the Navasota River in east central Texas. At this point the soldiers decided that they would not be able to find enough food to feed the expedition if they continued farther west, and thus the Moscoso expedition retraced its route back to the Mississippi River in Arkansas.
In 1942 Rex Strickland used historical, archeological, linguistic, and geographical sources to provide a detailed reconstruction of the army's route through Texas. He suggested that the army entered the state near Texarkana and then moved south along a trail that later became known as Trammel's Trace, until it reached the vicinity of what is now San Augustine. Here the expedition turned westward and traveled as far as the Trinity River. At this point they abandoned their hopes of reaching New Spain by land, and they returned along the same route.
Later, renewed efforts were made to understand the expedition's route through Texas. Charles Hudson, working in cooperation with the De Soto Trail Study authorized by Congress in 1987, suggested that the army entered Texas from northwestern Louisiana and moved west along Big Cypress Creek; it then turned south and traveled down the Neches River into what is now Angelina County. In his theory the expedition then turned back to the north and finally traveled west, reaching the Trinity River before it abandoned hopes of reaching New Spain overland.
More recently, James Bruseth and Nancy Kenmotsu reconstructed the Moscoso route by relying heavily upon the location of sixteenth-century archeological sites, and, following the lead of Strickland, upon trails that likely existed at the time of the expedition. Bruseth and Kenmotsu bring the army into Texas from Oklahoma. The prominent village site of Naguatex that is mentioned in one of the narratives is argued to have existed along the Red River in what is now Red River or Bowie county. From this point the army traveled south along either Trammel's Trace or the Jonesborough-to-Nacogdoches trail. Both historic roadways connect major prehistoric Caddo Indian villages in East Texas and almost certainly represent prehistoric trails used for many hundreds of years by the Indians. The army moved south to a point near what is now Nacogdoches; turning west it traveled on a trail that later became known as the Old San Antonio Road. The army went as far as the Guadalupe River near the Hill Country but then at this point turned back toward the Mississippi River in Arkansas. During the winter of 1542–43 the Moscoso expedition camped at the Mississippi and constructed boats for a return by water to New Spain. On July 2, 1543, they started down the Mississippi River, and on September 10 some 311 expedition members reached the Pánuco River, which forms the boundary between the states of Veracruz and Tamaulipas, Mexico.
While the expedition failed to find the gold and other riches that similar Spanish explorations had encountered in Central and South America, it did make the first major exploration into the interior of the North American continent and provided some of the earliest observations of Native American peoples, including the Caddo Indians of Texas. Recent scholarship has noted that this expedition and other Spanish explorations at roughly that same time introduced European diseases to the Indians. Large-scale epidemics occurred that appear to have caused the destruction of many Native American societies and resulted in the death of a significant portion of the southeastern Indian population, including many of the Caddo Indians.
An important map came out of the expedition. Known as the Soto map, it begins at Punta de Santa Elena (South Carolina) and describes the Atlantic coast south to the Florida cape and then around the gulf to Pánuco. The map was the work of Alonso de Santa Cruz.