An important philosophical tradition identifies persons as those entities that have minds, such that mind perception is a window into person perception. Psychological research has found that human perceptions of mind consist of at least two distinct dimensions: agency (e.g. planning, deciding) and experience (e.g. feeling, hungering). Taking this insight into the semantic space of natural language, we develop a generalizable, scalable computational-linguistics method for measuring variation in perceived agency and experience in large archives of plain-text documents. The resulting text-based rankings of entities along these dimensions correspond to human judgments of perceived agency and experience assessed in blind surveys. We then map both dimensions of mind in historical English-language corpora over the last 200 years and identify two salient trends. First, we find that while women are now described as having similar levels of agency as men, they are still described as more experience-oriented. Second, we find that domesticated animals have gained higher attributions of experience (but not agency) relative to wild animals, especially since the rise of the global animal rights movement in the 1980s.