Answer:
The Mississippi river.
Step-by-step explanation:
The regions along the Mississippi river was widely used for 2 commodities. Sugar plantations and cotton plantations.
Creating the plantations near the rivers have two main advantages. First, it provide close proximity to water sources that can be used to grow the crops. Second, it made it easy for the owners of the plantation to distributes their products to another states using boats. Both of these effectively cut down the cost of production and brought in more revenues for the plantation owners.