I used the keywords "Latin America" in MERLOT and found 185 results which include textbooks as well as assignments and textbook companions: https://www.merlot.org/merlot/materials.htm?keywords=Latin+America&sort.property=relevance
A federally funded collection of OER based at the University of Texas that offers primarily foreign language educational resources, Here is the link to Spanish-related OER materials:
Spanish literature with a thematic focus on legends and archetypes. It presents Romanticism in the context of nineteenth-century literary and social movements. It is designed as a first anthology for intermediate Spanish students at American universities. Although brief, it includes poetry, drama in verse and short story. The works have been selected for their literary interest and the social importance of their themes. They are all by canonical authors.
New for the Second Edition: over 4000 vocabulary, historical and cultural annotations to facilitate reading and comprehension.
A detailed Table of Contents is included on Open Textbook’s detail page in addition to the PDF of the relevant text.
A critical anthology of literary texts from the Spanish-speaking world. A focus on canonical authors and an attempt to include voices that have been marginalized. Each text includes an introduction and annotations created by students.
A detailed Table of Contents is included on Open Textbook’s detail page in addition to PDF and eBook copies of the relevant text.
The book is divided into the 3 following sections:
1. Políticas públicas y desigualdades de género: fortalezas, debilidades, desafíos
2. Los Derechos Humanos como marco político para la formulación yla acción pública
3. La agenda de género en las agendas institucionales del Estado