2. During the 19th century cities like St. Louis, Missouri, Omaha, Nebraska, and Topeka, Kansas, grew rapidly largely because of the development of

busy port and trade connections

Explanation:

The first set of municipal legislators were elected in 1808 and then nine years later, in 1817, the first steamboat known as Zebulon pike, arrived St. Louis. It took the steamboat 30days to get to St. Louis from Louisville, Kentucky and that improved connections with New Orleans and eastern markets.

By 1821, Missouri was admitted as a state and a year later, St. Louis was incorporated as a city in 1822 and continued to evolve rapidly due to the busy port and trade connections.