When did the US constitution become the official law of the land

March 4, 1789

Explanation:

when the first session of Congress began according to the standard legal account, the Constitution became efficative as law.

the emancipation proclamation was the aim of the war change to include the freeing of slaves in addition to preserving the union. the 13th amendment, which abolished slavery in the u.s. was passed on december 6th 1865.

as promised, lincoln waited to unveil the proclamation until he could do so with success from the union military advance. on september 22nd 1862, after a victory at antietam, he publicly announced a preliminary emancipation proclamation, declaring all slaves free in the rebellious states as of january 1st 1863.

civil disobedience, refusal to obey the demands or commands of a government or occupying power, without resorting to violence or active measures of opposition