Part 1 of Episode 4 surveys the lives of Thomas Jefferson and William Clark prior to the expedition. We actually note an earlier attempt by Jefferson and friends arrange an expedition between the Mississippi and the Pacific while he was living in France, as U.S. Minister (Ambassador) to France.

Part 2 takes a look at what happened to Meriwether Lewis after the Expedition, then follows the history of Clark's son and grandson, both named after Meriwether Lewis. That history of that namesake leads to an institution and an event that is part of modern America today.

In Part 3, Lena gets called to a hastily assembled choir practice, so Ole delivers the books from Lena's sister in St. Paul to the library. In the process, he befriends the librarian's grandson, and makes a new friend.