Heightened concerns about the health of the teaching profession highlight the importance of studying the early teacher pipeline. This exploratory, descriptive article examines preservice teachers' expressed motivation for pursuing a teaching career. Using data from a large teacher education program in Texas, we use a natural language processing algorithm to categorize into topical groups roughly 2,800 essay responses to the prompt, "Explain why you decided to become a teacher." We identify 10 topics that largely reflect altruistic and intrinsic (although not extrinsic) reasons for teaching. The frequency of topics varied substantially by preservice teacher gender, race/ethnicity, and certification area. Intrinsic enjoyment of teaching and experiences with adversity predicted higher clinical teaching performance and lower attrition as a full-time teacher.