Final answer:
Canals and railroads competed due to technological advancements and the need for faster and cheaper transportation methods. Railroads ultimately became the dominant means of transport due to their faster delivery times and ability to connect port cities to the interior.
Step-by-step explanation:
The competition between canals and railroads was the result of technological advancements and the need for faster and cheaper transportation methods. Canals were the main route of commerce before the advent of rail and remained rail's biggest competitor for some time. While steam locomotives were faster, shipping costs were cheaper by canal. However, by the 1850s, the railroad network had grown and become the dominant means of transport, due to its faster delivery times and ability to connect port cities to the interior.