Officer's uniform at Cole Creek Landing. Both Lewis and Clark worn these formal dress uniforms on special occasions. Technically, Lewis was a captain and Clark was a 2nd Lieutant but during the Expedition Clar carried the unofficial rank of captain in order have the same rank and authority as Lewis. Lewis had promised Clark that he would be promoted to Captain but it was apparently not in his authority and Clark resigned the military before he was promoted. It was not until President Clinton was in office that Congress voted to retroactively promote Clark to the rank of Captain.