Between 2006 and 2016, American universities experienced a significant decrease in student enrolment in foreign language (FL) courses. This decrease corresponded with the dissolution of over 650 foreign language programmes between 2013 and 2016. Using self-determination theory (SDT) as its theoretical framework, this study sought to advocate for the growth of university FL programmes by identifying differences in the motivational orientations, levels of basic psychological need satisfaction, reasons for learning a new language and course enrolment plans of 236 American undergraduate students enrolled in elementary and intermediate level FL courses. Results indicated that competence- and relatedness-supportive learning environments that support students' autonomous, integrative and altruistic motivations for language learning have a strong, positive relationship with undergraduate FL learners' decisions to enrol in an unrequired language course in the next semester. The findings recognise all FL programmes as agentic forces in language advocacy and programme growth. Recommendations for language educators are discussed.