Each state retains its sovereignty, freedom and independence, and every power, jurisdiction and right, which is not by this confederation expressly delegated to the united states, in congress assembled.
— article ii, articles of confederation
the powers not delegated to the united states by the constitution, nor prohibited by it to the states, are reserved to the states respectively, or to the people.
— 10th amendment, united states constitution
the purpose of each of these provisions is to
(1)determine the division of power between state and central governments
(2)create a process for allowing amendments
(3)grant the central government power to control the states
(4)limit the power of the executive branch

answer: secession

secession, as it applies to the outbreak of the american civil war, comprises the series of events that began on december 20, 1860, and extended through june 8 of the next year when eleven states in the lower and upper south severed their ties with the union. the first seven seceding states of the lower south set up a provisional government at montgomery, alabama. after hostilities began at fort sumter in charleston harbor on april 12, 1861, the border states of virginia, arkansas, tennessee, and north carolina joined the new government, which then moved its capital to richmond, virginia. the union was thus divided approximately on geographic lines. twenty-one northern and border states retained the style and title of the united states, while the eleven slave states adopted the nomenclature of the confederate states of america.

explanation:

according to worldatlas.com, the u.s. has an 86% literacy rate.