'All knew that this interest was, somehow, the cause of the war. To strengthen, perpetuate, and extend this interest, was the ob
ject for which the insurgents would rend the Union even by war; while the government claimed no right to do more than to restrict the territorial enlargement of it". - President Abraham Lincoln, second inaugural address, 1865 In the excerpt above, what does "this interest" refer to?
(10 points)
A.
The Confederate States of America
B.
Protective tariffs
C.
Slavery
D.
The U.S. Constitution