Answer: because the authority of judicial review can declare that laws and actions of local, state, or natioanl government are invalid if tehy contradict the Constitution.
Slavery played the central role during the American Civil War. The primary catalyst for secession was slavery, especially Southern political leaders' resistance to attempts by Northern antislavery political forces to block the expansion of slavery into the western territories.
There are a lot different answers to this question so what specific things are you looking for?
The Spanish then The United States
