Answer:
I think it is D.Factories
Explanation
Around this time the economy in the US became very industrial because of the fall of agriculture since a lot of farmers moved north to work in factories
By roughly 6000 to 8000 years ago, agriculture was well under way in several regions including Ancient Egypt, around the Nile River; the Indus Valley civilization; Mesopotamia, between the Tigris and Euphrates rivers; and Ancient China, along the Yellow and Yangtze rivers.
"<span> ...do order and declare that all persons held as slaves within said designated States, and parts of States, are, and henceforward shall be free; and that the Executive government of the United States, including the military and naval authorities thereof, will recognize and maintain the freedom of said persons." THIS IS THE MAIN IDEA OF THE EMANCIPATION PROCLAMATION. </span>
