Question

The steady progress of industry in the United States was possible because

Answer 1

D. all of the above, coal and oil were discovered
new inventions were created
telegram and railroads were built

Answer 2

Answer:

d. all of the above

Explanation:

The industry evolved with creative and revolutionary technologies in such a way that the progress was very steady. There was new energy sources, new production methods, new methods of transportation and the more developed industry would become to the market, the more things it could use to further develop itself.