Federal Government's Role in Pre-Civil War Tensions

Source: The diary of John Quincy Adams, 1820.

The division in Congress and the nation is nearly equal on both sides. The argument on the free side is, the moral and political duty of preventing the extension of slavery in the immense country from the Mississippi River to the South Sea. The argument on the slave side is, that Congress have no power by the Constitution to prohibit slavery in any State, and the zealots say, not in any Territory. The proposed compromise is to admit Missouri, and hereafter Arkansas, as states, without any restriction upon them regarding slavery, but to prohibit the future introduction of slaves in all Territories of the United States north of 36º 30’ latitude. I told these gentlemen that my opinion was, the question could be settled no otherwise than by a compromise.

To what extent and in what ways were the actions of the federal government responsible for the increasing social and political tensions between the North and South prior to the Civil War?