I think the answer is D but I could be wrong
After the civil war, much of the ownership for land was unattainable for free slaves due to the government opposing the idea. Instead most African slaves had to become sharecroppers on plantations where they had previously been slaves.
The line was important because it was established that any new western state that would be south of the line could be a slave state, while any new state in the west north of the line would be a slave free zone. This was done according to the Missouri compromise when slavery was an issue once more in 1850. The line also became the northern border of Texas when it was later added to the union.
Answer: The introduction of barbed wire prevented cattle from walking freely across the plains as they had done in the first half of the 1800s.
Explanation:
