We present a curricular intervention in elementary Spanish heritage language in a Hispanic serving institution located in the US Northeast (Bronx, NYC), that aims to contextualize Latinx students' experiences and perceptions of Blackness within broader histories of oppression and enslavement. Our practice brings together critical Latinx pedagogy and critical approaches to Spanish heritage language education to facilitate sociohistorical consciousness for both language instructors and students through the use of open-access Latinx archival resources. We outline a three-week unit designed using the First Blacks in the Americas online collection curated by the City University of New York Dominican Studies Institute. During the unit, the students practice their full linguistic repertoires and develop historical thinking skills. We discursively analyze survey responses, instructor fieldnotes, and students' coursework collected throughout the course to measure the impact of this pilot project. We find that students value learning about Latinx history as a mechanism to practice their Spanish, especially as it relates to the (internalized) racism they experience within their families and communities. We discuss the implications of a critical Latinx language pedagogy to anchor Spanish language education in the experiences and knowledge of Latinx people, histories, and cultures.