This very brief journal article describes the “Nahualismos” (Nahuatl loan words also known as Mexicanismos or Aztequizmos) of the Los Adaes community in what is now Louisiana (USA). This settlement was established in 1720 by the Spanish and was the Tejas (Texas) capital until 1770 when it was moved to San Antonio de Bexar (San Antonio, TX). The community has a very interesting history; their descendants are a mixture of Spanish, French, Adais (local indigenous group associated with the Caddo), and Apache captives. Some scholars posit that there might have also been some runaway slaves and other indigenous peoples associated with this community. Something to keep in mind as well, the term “Spanish” as an identifier in the colonial era did not necessarily mean that the indidvidual was 100% pure Spanish; the term came to be used as a class signifier, so mixed and indigenous people could “pass” for Spanish if they conformed to the Spanish culture of their time. There is a possibility that some of the Spanish settlers in Los Adaes were actually Tlaxcalteca (Tlascalan) or from some other indigenous group from Mesoamerica.
In any case, the link above provides a small list of Nahuatl loan words from a rapidly vanishing “Spanish” dialect, one of the oldest European dialects in the US.
Link: Los Adaes (UT-Austin history webpage, 10 pages well worth the read for Texas history enthusiasts)