Who’s demands? You should put your question in more detail if you want an answer....
The answer is election of 1860
The 1860 election happened when during the rise of major political groups that have differing principles.
The Republicans strongly support the abolishment of slavery while the democratic party support to keep the slavery system.
In the end , The Republican party (that led by Abraham Lincoln) won that election.
I would go with c not the other ones
To combat the threat of tropical diseases such as malaria and yellow fever, the United States decided to use new measures to eradicate the disease before the construction of the Panama Canal. Under the leadership of Colonel William Crawford Gorgas, many changes were made. When it was discovered that mosquitoes were the source of the disease, Gorgas who was appointed as the head of hospital and sanitation, he made sure that containers with stagnant water were removed because mosquitoes lay their eggs there. He also built domestic water systems to eliminate the need to collect rain water. Prophylactic Quinine was supplied to the people in the area and fumigation and oiling of streams were launched. Those who were sick were quarantined and workers would sleep in screened structures so that mosquitoes would not be able to bite them. These programs resulted in the successful elimination of tropical diseases in the area and the health of workers improved.
