Which does not describe a benefit enjoyed in the mid-1800s by american cities that grew up along rivers?

Although you didn't include any options t choose from, I found that the major benefits enjoyed in the mid-1800s by American cities that grew up along rivers are water power for mills and factories, transportation by steamboat, and drinking water. One major benefit they didn't enjoy however, was hydroelectric power.

The transcontinental railroad provided a means of fast transportation. it cut a 6 month trip into 6 days, created jobs for many people and encouraged immigration. the homestead act played a huge role in western expansion; it allowed settlers to begin a fresh start, and gave them land in exchange for their residence for up to five years and a small fee.