Read the passage. In 1803, Congress approved the treaty that finalized the Louisiana Purchase. The size of the United States almost doubled. Jefferson still held hope that the territory contained the famed and elusive Northwest Passage, a water route from the eastern United States to the Pacific Ocean, but because this land had not yet been explored by White settlers, Jefferson and Congress were in the dark about exactly what they had purchased. Jefferson sent Merriweather Lewis, his private secretary, and William Clark, an associate of Lewis’s, to explore the territory. Without the help of Sacajawea, a Shoshone woman Lewis and Clark met in the Rocky Mountains, it is unlikely their expedition would have been as successful as it was. Which text structure is used in this passage? chronological order compare/contrast description problem/solution