What waterways became increasingly popular in the 1820s and 1830s, particularly in the mid-Atlantic states, with the Erie being the most famous?

The option referring to canals is correct because during the 1820s and 1830s, there was a significant surge in the construction and use of canals in the United States, particularly in the mid-Atlantic states. The Erie Canal, completed in 1825, serves as a prime example of this trend. It connected the Hudson River to Lake Erie, facilitating the movement of goods and people between the Atlantic Ocean and the Great Lakes. This development greatly enhanced trade and transportation efficiency, allowing for lower costs and faster shipping times compared to other means of transport at the time.

Canals played a crucial role in the economic expansion of the region, promoting the growth of cities and contributing to the overall industrialization of the United States. As such, they became vital conduits for commerce and contributed significantly to westward expansion, making them a key feature of the early 19th-century American landscape.