Within mathematics education in the United States, educators and scholars have worked to identify ways of using language that students of mathematics must perform. I describe how mathematics educators from 1650–1945 have argued whether or how language is important for learning and doing mathematics. Framing these arguments as a form of language policy and planning, I apply intertextual research methods (Johnson, 2015) and the framework of enregisterment (Agha, 2007) to present explicit and implicit policy and planning for math language as intertextually linked models of linguistic behavior. I also summarize the gradual development of math language alongside wider shifts in the structure and philosophy of education in the United States. While early attention to language and mathematics learning did not produce expectations for student language use, student-regulating models of math language eventually solidified through the context of progressive education scholarship in the early 20th century