Teach PA History
Philadelphia's Important Contribution to the Lewis and Clark Expedition
What to Know
Teaching Time
2 40-minute class periods
Grade Level
Middle School
  • Reading, Writing, Speaking and Listening
  • History
Historical Period
  • Expansion and Reform - 1801-1855
Thomas Jefferson had a vision of exploring the western area of North America even before the purchase of the Louisiana Territory in April of 1803. As President, he wrote a secret letter to Congress in January of 1803 requesting funds for such an expedition. Jefferson's request to Congress was focused on the commercial aspects of possible trade with the Native Americans. The letter was secret because of the possible political implications of a U.S. exploratory trip into what, at that time, was another country's territory. While Jefferson made no mention to Congress of any scientific purposes for the trip, he definitely had them in mind. After receiving an appropriation of $2500.00, Jefferson quickly began putting his plan into action. Then the unexpected opportunity of the Louisiana Purchase added to Jefferson's desires to learn as much as possible about the newly acquired lands. He wanted the expedition to map and explore the unknown territory; report on climate conditions; send back samples of the soil, minerals, plant and animal life they were to study; look for fossils and signs of mastodons; learn about Native Americans tribes and trade possibilities with them; and search for a water route to the Pacific. It was a monumental mission that required extensive preparation. President Jefferson asked Captain Meriwether Lewis, his personal secretary, to lead the expedition. Jefferson understood Lewis's need for an education in the sciences, so he decided to send him to the nation's center of culture and learning - Philadelphia. The Philadelphia area was also the leading center for trade and the place where Lewis could locate specific supplies he needed to purchase for the trip. Lewis was in the Philadelphia area from April to June of 1803, and it was during that period that he was mentored by the greatest scientific minds of the day. It was under the guidance of Andrew Ellicott, Benjamin Rush, Benjamin Barton, Robert Patterson, and Caspar Wistar that Lewis learned the skills he needed to accomplish the directives of his mission. It was in the Philadelphia area where Lewis found the necessary supplies he needed for the expedition, and where he spent $2,324.00 of the Congressional appropriation allotted for the trip.


Students will: 1. analyze a primary source document (Jefferson's secret letter to Congress) and identify its objectives through the aid of focus questions. 2. identify Philadelphia experts with their area of expertise through use of a graphic organizer after they have read about and analyzed the experts" contributions. 3. analyze and interpret the data in a list of supplies purchased for the expedition through a small group activity. 4. write a newspaper editorial summarizing the contributions of Philadelphia to the Expedition.

Standards Alignment

  • History

    8.1.9. B. Analyze and interpret historical sources.
    8.1.9. D. Analyze and interpret historical research using primary sources.

  • Reading, Writing, Speaking, and Listening

    1.4.8. C. Write persuasive pieces.

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