The fake news you learned in government school.

https://www.lewrockwell.com/2017/12/walter-e-williams/independence-hypocrisy/

Catalonia, Bavaria and Veneto are relatively prosperous jurisdictions in their countries. They feel that what they get from the central governments is not worth the taxes they pay. Each wants the central government off its back. They think they could be far more prosperous on their own. That should sound familiar. Some of the motivation for secessionist movements in Europe is similar to the motivation found in the Confederacy’s independence movement of the early 1860s.

Throughout most of our nation’s history, the only sources of federal revenue were excise taxes and tariffs. In the 1830s, the North used its power in Congress to push through massive tariffs to fund the government. During the 1850s, tariffs amounted to 90 percent of federal revenue. The Southern states were primarily producers of agricultural products, which they exported to Europe. In return, they imported manufactured goods. These tariffs fell much harder upon the export-dependent South than they did upon the more insular North. In 1859, Southern ports paid 75 percent of federal tariff revenue. However, the majority of the tariff revenue generated was spent on projects that benefited the North.

Tariffs being a contributing cause of the Civil War is hardly ever mentioned. Using the abolition of slavery as an excuse for a war that took the lives of 620,000 Americans confers greater moral standing for the Union.