Final answer:
Andrew Foster was the first of three Black deaf students to be enrolled at Gallaudet University, marking a significant moment in the institution's history.
Step-by-step explanation:
The first of three Black deaf students to be enrolled at Gallaudet University was Andrew Foster. Known for his significant contribution to deaf education, especially in Africa, Foster was a pioneer who opened up numerous schools for the deaf across the continent. His enrollment at Gallaudet represented a landmark moment in the history of education, as the university is a prominent institution for the higher education of the deaf and hard of hearing.