Both the philanthropy and the self-interest of the master have combined to produce this humane result."[104]
Buchanan thought restraint was the essence of good self-government. He believed the constitution comprised "... restraints, imposed not by arbitrary authority, but by the people upon themselves and their representatives. ... In an enlarged view, the people's interests may seem identical, but to the eye of local and sectional prejudice, they always appear to be conflicting ... and the jealousies that will perpetually arise can be repressed only by the mutual forbearance which pervades the constitution."[105] Regarding slavery and the Constitution, he stated: "Although in Pennsylvania we are all opposed to slavery in the abstract, we can never violate the constitutional compact we have with our sister states. Their rights will be held sacred by us. Under the constitution it is their own question; and there let it remain."[103]

James Buchanan's House, Wheatland.
One of the prominent issues of the day was tariffs.[106] Buchanan was conflicted by free trade as well as prohibitive tariffs, since either would benefit one section of the country to the detriment of the other. 