Cross-border migration is increasing in a globalized world. On the physical borderlands, migration across and between borders occurs on a habitual basis. This qualitative study employs semi-structured interviews to explore how three "transfronterizo" teachers along the U.S.-Mexico borderlands draw on their backgrounds and lived experiences as they go about in their English teaching practices. Findings suggest that the diverse lived experiences of the three teachers allow them to develop a particular knowledge, consciousness, and agency in creating a third space, or a "mundo zurdo," in which they advocate for their "transfronterizo" students.