Each stste believed they had the right to decide whether to obey a federal law or declare it null and void

This is what occurred during the nullification crisis of 1832 to 1837, in which there was a confrontation between the federal government and the South Carolina in respect of a law made by the federal government. During this time, John C. Calhoun, who was a supporter of state's rights hold that South Carolina has the right to nullify or ignore federal law which they believe are wrong. The issue of nullification crisis is one of the factors that led to civil war in the United States.

Both countries had to aprove annexation.