Bates wrote letters to Lewis's superiors accusing Lewis of profiting from a mission to return a Mandan chief to his tribe. Because of Bates' accusation, the War Department refused to reimburse Lewis for a large sum he personally advanced for the mission. When Lewis's creditors heard that Lewis would not be reimbursed for the expenses, they called Lewis's notes, forcing him to liquidate his assets, including land he was granted for the Lewis and Clark Expedition. One of the primary reasons Lewis set out for Washington on this final trip was to clear up questions raised by Bates and to seek a reimbursement of the money he had advanced for the territorial government.