t. Louis, Sept. 23, 1806 -- Capt. Meriwether Lewis and William Clark returned here today. They led an expedition which took them across the vast Louisiana Territory. The 43-man expedition left here May 14, 1804. For 28 months they explored rivers and mountain ranges. They were led by a woman Indian guide named Sacajawea. The expedition's purpose was to establish friendly relations with Indians and map the area. Which of the following answers the "when" question? Question 1 options: 1806 1804-1806 28 months