By the 1840s steamboats were facing increasing pressure from B. Trains.
Steamboats became widely used in the early 19th century when they began to replace wind-powered boats which used sails.
Their dominance did not last for long however because by the mid 18th century, railroads were increasingly being built which allowed trains to carry goods to areas that ships couldn't at a faster rate.
Steamboats therefore did not get to enjoy much of their dominance as a result of trains being increasingly used by people to transport goods and services.
More information on the railroads can be found at https://brainly.com/question/14651201.
