After the Civil War, the United States: a - became more industrial
b - made advancements in communication and transportation.
c - grew to be one of the world's wealthiest countries.
d - All of the choices are correct.

D All of the choices are correct.

i guess it should be d option i en all of the above

the right answer is the third one: turnpikes went short distances to connect markets. turnpikes, also known as toll roads, were very important for trade and transportation (of people, goods and products) in the 19th century, coinciding with the expansion towards the west. they contributed significantly to the economic development of the united states.