This was the principle that a state government can declare a law of the national government invalid within the borders of the state

The correct answer is Nullification Crisis

The period of US history between 1815 and 1865 is marked by two distinct events: the beginning of American westward expansion and the growing political, social and economic divide between the northern and southern states on controversial issues - especially on slave labor - culminating in the American Civil War, which began in 1861 and extended until 1865.

would it be plagiarism to copy and paste off of here? ?

answer; majority;