Alas, two mistakes in that post.
Exports had no tariff. Cotton was an export. Though the US Navy provided security for Southern Cargos (often in New England ships) the Cotton and Tobacco exports were not taxed.
Imports were taxed. If the South imported goods from the North, they paid no tax at all. If they imported goods from England/Europe, they paid Tariff.
and the share of representation for slaves was 3/5ths.
The basic facts are still true.
The North enjoyed a system where the south was paying through the nose for goods and services from them as well as funding the federal government with a major portion of the southern profits. Tariffs were used to protect the industries of the north and to supply those industries with cotton from the south at a cheaper price then it was being sold overseas.
The South felt so threatened and punished by these tariffs that the civil war wasn't the first time they tried to secede to escape the tariffs. The first time was in 1832 during the Nullification Crisis which was solved peacefully.
Nullification is the legal theory that is at the very heart of the states rights argument that say that a U.S. State has the right to nullify, or invalidate, any federal law which that state has deemed unconstitutional.
Or in other words a state can ignore any federal law it chooses to, The basis of this argument is that the states have the right to legislate anything not covered by the Constitution and therefore since the Constitution doesn't say they can't ignore federal law then they can ignore it or nullify it within state lines. As a legal argument it is almost like saying your mom said you couldn't play in the street so let's go play on the highway. It is the core of the whole states rights argument.
By becoming a state of these United States, a nation, territory, or area like Texas for example chooses to give up its sovereign right as a nation to be a smaller part of a whole union and choose to obey the Constitution.
"Yeah so" Well under the Constitution the states are prohibited from doing certain things that only the nation as a whole is allowed to do.
Article I. - The Legislative Branch
Section 10 - Powers prohibited of States
No State shall enter into any Treaty, Alliance, or Confederation; grant Letters of Marque and Reprisal; coin Money; emit Bills of Credit; make any Thing but gold and silver Coin a Tender in Payment of Debts; pass any Bill of Attainder, ex post facto Law, or Law impairing the Obligation of Contracts, or grant any Title of Nobility.
No State shall, without the Consent of the Congress, lay any Imposts or Duties on Imports or Exports, except what may be absolutely necessary for executing it's inspection Laws: and the net Produce of all Duties and Imposts, laid by any State on Imports or Exports, shall be for the Use of the Treasury of the United States; and all such Laws shall be subject to the Revision and Controul of the Congress.
No State shall, without the Consent of Congress, lay any duty of Tonnage, keep Troops, or Ships of War in time of Peace, enter into any Agreement or Compact with another State, or with a foreign Power, or engage in War, unless actually invaded, or in such imminent Danger as will not admit of delay.
It doesn't take a legal scholar to figure that almost everything that The Constitution says the states are prohibited from doing those states that seceded from the United States during the Civil war did even though in joining the United States they gave up their sovereign right to do so. That's where the state rights argument really falls apart, states are not mini nations, they give up all sovereign rights as a nation to be part of a greater nation.
Which is something all the little confeder-buddies just don't understand or comprehend.