Searching for origin stories of the American Cowboy I stumbled on this post. It has no references to document the claims, but it looks like a good starting point for further research. Ms. Castille also made a documentary; “A Louisiana Horse Story”, you can watch the trailer.
“On this “vast meadow of America”, trading posts were established as early as the 1730s by Europeans who traveled from New Orleans with slaves to tend to these posts. On their return, it was the slave who was left behind to form business and personal relationships with the Native American cattle and horse traders in the region. Even before the Acadians arrive and transform the cattle industry through the Dauterive Compact, these slaves became the first vachers, or ranchers, in the territory. Oral histories, public records, and branding books identify the early ranchers as Indians, women, and gens de couleur libres, or free people of color. Together, these people formed what is called the Creole population, and are considered by most to be the birth of some of America’s first cowboys: French, Black, and Indian.
When the Acadians arrive in 1765, they were encouraged through the Dauterive Compact to pursue cattle ranching. For some, this is seen as the start of the American cattle industry. The compact specifies that:
Mr. Dauterive promises and obliges himself to furnish five cows with calves and one bull to Acadian families…. the said Acadians have accepted purely and simply and have promised and obliged themselves to take care of said cattle.
The prairies offered opportunities to people who had little or no land. In contrast to the plantation model, which demanded large plots of land, no land ownership was required to raise cattle.”
From “A HORSE TALE FROM THE LOUISIANA PRAIRIE” By Conni Castille
And listen to her “Horse Radio Show” at https://soundcloud.com/conni-castille