For the most part, the CSA’s constitution was a word for word copy of the US Constitution.  Therefore, you can find many similarities quite easily.  For example:

-Both constitutions ban the international slave trade.
-Both constitutions provide for a bicameral national legislature.
-Both constitutions have the same system in which Representatives are elected for 2 year terms and states are represented in proportion to their populations where Senators are elected for 6 year terms and each state has 2 of them.
But there were some significant differences that were related to, as one might expect, issues of slavery and of states’ rights.Slavery is explicitly mentioned and indeed guaranteed by the CSA’s constitution. For example, in Article I, Section IX there is a clause sayingNo bill of attainder, ex post facto law, or law denying or impairing the right of property in negro slaves shall be passed.The CSA’s constitution allowed for presidents to serve one term only and that term was to be 6 years.The CSA’s constitution is much more explicit about limiting the powers of the federal government.  For example, Article I, Section VIII does not have the clause that allows the US Congress to provide for “the general welfare” of the country.  Instead, it says the CS Congress can only impose taxes that arenecessary to pay the debts, provide for the common defense, and carry on the Government of the Confederate States.