Then tell the class why they saw fit to throw such high tariffs on them?
You are getting down-right silly GOP.
Look up the debates on the bill. It could be anything. Maybe they were simply retained from the 1857 tariff. Maybe they were hoping to gain warehousing revenues from goods with a final destination elsewhere. Maybe they were hoping that some idiot would come along and try to import things that he could get for half the price at home without the tariff.