What was the most important geographical feature in the louisiana purchase and why?

Mississippi River would be the correct answer. The Mississippi River now aloud people to ship goods from the south to the north and visa versa.

The Mississippi was the most important natural geographical feature in the Louisiana purchase because it allowed for the United States government to purchase a lot of land from the Mississippi river to the rocky mountains which is a lot of land, and would be beneficial to the government and united states all together in the Louisiana purchase.