Explain why the railroad and steel industries were interdependent during the 19th century?

I'm most likely gonna be wrong on this but correct me if i am wrong

Explanation: farmers demanded regulation of railroads because it was expensive and they sold to other businesses than other settlers so they profited from it.

That's what I could think of so basically it was a way to gain more money in the end.

I hope this helped

the award is named for an american naval historian and theorist, rear admiral alfred thayer mahan, united states navy who, through his writing, provided stimulus and guidance to those who share in the defense of the nation.

what are the options?