Lewis's record as an administrator is mixed. He published the first laws in the Upper Louisiana Territory, established roads and furthered Jefferson's mission as a strong proponent of the fur trade. He negotiated peace among several quarreling Indian tribes. His duty to enforce Indian treaties was to protect the western Indian lands from encroachment, which was opposed by the rush of settlers looking to open new lands for settlements. But due to his quarreling with local political leaders, controversy over his approvals of trading licenses, land grant politics, and Indian depredations, some historians have argued that Lewis was a poor administrator.