They found coal and iron and disciplined workers, a growing population, and a technologically advanced society with research.
the answer is c i believe ;)
The words that are missing in the sentence are The Second Great Awakening and moral renewal. The so-called Second Great Awakening is referring to revival of religious during the early nineteenth century, where the preachers are advocating or sharing the message of spiritual and moral renewal to people.
Aside from connecting the East U.S. to the West U.S., the transcontinental railroad was also instrumental in driving a gap through the confederate territories and ending the reconstruction era. (Choices A and D are the answers.)
Hope my answer has come to satisfy your query.