The government of the Confederate States of America (CSA) was, for the short time that it lasted, fairly similar to the government of the United States. The CSA constitution was copied word for word from the US Constitution and then altered in a few ways. Please see the link below for a comprehensive, line-by-line look at how the two constitutions differed. The main differences between the two systems of government had to do with the CSA’s fear of centralized authority.
The major similarity is that both governments were democracies with presidential systems. In both governments, leaders were elected by the people or by their elected representatives. In both systems, there were three branches of government with checks and balances and separation of powers. In both systems, there was a bicameral legislature. In other words, the basic structures of the two governments were essentially similar.
The differences between the two governments existed because the CSA did not want its national government to be as powerful as the US government was. The CSA was seceding for the sake of states’ rights (specifically, their right to hold slaves) so it had to weaken the national government and give its states stronger rights. Because of this, the CSA Congress did not have as many powers as the US Congress did. It could not, for example, fund infrastructure projects because those would be left to the states. It could not tax the people of the states as easily as the US Congress could. In its preamble, the CSA constitution said that it was created by “each State acting in its sovereign and independent character.” This is meant to show that the states were independent and that the national government had very little power over them.
There were a few other cosmetic differences between the two governments. Perhaps the most notable is that the CSA president was to be elected for a 6 year term and could not be reelected. In addition, the CSA constitution explicitly protects the right to own slaves. However, as far as differences in the actual structure of government, the main differences are those mentioned in the previous paragraph.