Today, about 350 languages are spoken and signed in the United States, many of which are heritage languages (HL). A HL is a language to which a speaker has an ethnic, historical, or sentimental connection. This dissertation reports on an ethnographic case study on the language and literacy socialization practices of one trilingual family (English, Spanish, Portuguese) in their efforts to maintain Portuguese as their HL. The analysis of data focuses on three themes: (1) HLM activities during their religious practices; (2) the emotions connected to HLM; and (3) the family's HLM practices when they travel to Brazil. Through a qualitative analysis of participant observation fieldnotes, interviews, and video recorded interactions as the family engages in heritage language socialization practices at home, in their community, and during travel to visit extended family in Brazil, I examine specific discourse strategies employed by the family in their maintenance efforts, giving attention to the linguistic, cultural, and religious ideologies that influence their communicative strategies. The findings expand knowledge and increase awareness on the topic of language socialization, cultural assimilation, and family language policy (FLP) in connection with HLM since family language negotiation strategies exert an undeniable impact on the outcome of HLM. Finally, this contribution also highlights the need for HL families, and all involved in HLM to recognize the emotions, attitudes, and language ideologies of heritage language speakers to fully harness their knowledge and aspirations. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]