a major reason why thomas jefferson was interested in purchasing louisiana from france was that he responses wanted to establish a precedent for the expansion of presidential authority wanted to establish a precedent for the expansion of presidential authority wanted an area beyond the mississippi river to which eastern native americans (indians) could be moved wanted an area beyond the mississippi river to which eastern native americans (indians) could be moved had learned from lewis and clark of the untapped mineral resources in western areas had learned from lewis and clark of the untapped mineral resources in western areas hoped to cement a franco-american alliance against the british hoped to cement a franco-american alliance against the british hoped to preserve an agricultural society by making abundant lands available to future generations