What effects did the lewis and clark expedition cause?

I hope this is right After the Lewis and Clark journey, Americans then knew that there was no water passage from the Atlantic Ocean to the Pacific Ocean. More of the interior geography of North America was mapped, as a result of this exploration. When Lewis and Clark returned, they were both promoted. This was an epic expedition that produced much information that helped develop this area of the U.S.

More than 4 million enslaved hunan beings in the south and they touched every aspect of the regions social, political and economic life.