Invite students to come to the class dressed as pioneers for the party. They can dress as a general western pioneer, characters from literature, such as the "Little House on the Prairie" book series by Laura Ingalls Wilder, or a famous explorer, such as Lewis and Clark. Award prizes for the best costumes.
Serve typical "pioneer" food to the students as refreshments, such as hot cakes, sausages and fried potatoes.
Teach the students old western songs and host a sing-a-long with the class.
Create a game show of the details of the western expansion, such as the Louisiana Purchase and the Lewis and Clark expedition. Offer prizes to the students and teams who earn the most points.
Ask the students to come up with skits depicting portions of the Lewis and Clark journey west. The skits can combine factual details with humorous renditions to promote the maximum entertainment value.