Answer:
D. St Louis
Step-by-step explanation:
St. Louis became a commercial giant. It was an important trade center, a supply point for the Mississippi. Because of the Rapids north of the city, St. Louis was the northernmost navigable port for many large boats.
St. Louis was transformed into a bustling boom town, commercial center, and inland port. More than 150 steamboats could be seen in St. Louis land at one time in the 1830s.
Lots of Immigrants especially from Germany flooded into St. Louis after 1840. During the period of Reconstruction, rural Southern blacks also came into St. Louis as well, seeking for greener pastures. St Louis grew to become a large commercial US city in the 1850s.