This paper analyzes the Kansa Indian language vocabulary collected by Prince Alexander Philip Maximilian of Wied-Neuwied during his journey through the plains of North America between 1832 and 1834. Prince Maximilian's word list is likely the oldest existent vocabulary on this language. His vocabulary, published in 1843 as an appendix to his travel journals, is then compared to more recent observations of Kansa words by James Owen Dorsey in the late 1880s and by the author in the 1970s. Observations about the phonology of Kansa are offered which, in turn, clarify the ultimate source of Maximilian's list. (MDM)