There is always a trigger. There is always a spark. Secession occurred in 1860, and you see Lincoln as the cause. I say he was simply a spark.
From at least 1807 to 1860 there was a constant struggle between northern and southern interests. This was the major political issue for 3 generations. Congress was constantly seeking compromises and a balance of power was constantly negotiated. Meanwhile, presidents were elected either as supporters of southern interests or as neutral figures who did not want to rock the boat. From Jackson through Buchanan, no president supported northern interests in preference to southern interests.
Lincoln became a spark simply because he was the first northern sympathizer to hold the office of president since JQ Adams. The political situation was hardly "light and transient". It was, in fact, intractable. States rights had been a bone of contention for our entire history and with the election of Lincoln, it appeared likely that the northern interests would become permanently dominant.
It was time to change the government. The union of the several states had changed, and the imposition of northern will had proceeded to an intolerable point. It seems clear to me that this is very analogous to the situation that caused Jefferson to write the Declaration of Independence in the first place.
A free people should be free to decide if they wish to participate in a particular political entity. The people of SC voted, and decided to leave. There is nothing in the Constitution which says this was improper. Lincoln, however, decided that their vote was worth nothing, and he ended up raising an army to invade his own country and impose his will on sovereign states. There is nothing in the Constitution which allowed him to do that.
Agreed. What’s more, there were several States that only pressed for secession after Lincoln went after SC. My home State (Commonwealth actually) of VA, for example, didn’t vote for secession until after Lincoln started demanding troops to invade SC.
You are exactly on target here but should also point out that there were several secession movements in the United States prior to 1860 and NONE of them occurred in the south. In fact, the right of a state to seceded was UNIVERSALLY accepted in the U.S. prior to about 1850.