How did the Lewis and Clark Expedition affect the frontier in the early 1800s? The frontier’s expansion increased rapidly after Lewis and Clark cleared the territory of any dangers.
Americans extended the frontier when they learned about the territory from the expedition reports.
The frontier’s expansion slowed after Lewis and Clark returned from their expedition disappointed by the lonely landscape.
Americans left the frontier untouched for another decade after they learned how dangerous the expedition was.

B. Americans extended the frontier when they learned about the territory from the expedition reports.

can i know the options so i can answer the qu

they had many gains 1 one freedom for slaves the major cause of the civil war is that the   north wanted freedom for slaves but the south didn; t creaitng the civil war

another gain they have is poltiical influence

poltiical influence is a big thing everywhere even now peoplle are always trying to get the head up in poltics thats what they did by giving the republicians a good name for freeing slaves