Answer:
The failure to bring missionaries
A land that had once run largely north-south<span> now ran east-</span>west. ... These changes mutually fueled the Second Industrial Revolution<span> which peaked ... River Valley, wheat in the </span>Midwest<span>, and manufactured goods in upstate New York.</span>
It's called an assembly line.
The Battle of Gettysburg was a major victory because it eliminated over 65,000 confederate soldiers. It was the bloodiest battle in the civil war.
Now I'm not 100% sure here but C is your best bet
