Oh, no. He did a lot more than nothing. He was instrumental in getting the Supreme Court to reach the decision they did in the Scott v. Sanford, easily the worst decision in the history of the Supreme Court. The case where the Court literally said that Black people were not and could not be citizens, and thus had no rights or protections. Buchanan cowtowed to the slave states at every opportunity, and many view his unwillingness to speak out against the secessions as tacit approval of them. There have been other presidents who were more corrupt (Harding, Nixon... and Trump will almost certainly take his place among that group once we are far enough away to get a full accounting of his time in office), but no president has ever failed and damaged this country more grievously than Buchanan.
And man's not wrong, feed your cats with golden spoons.