One aspect of the Commercial Revolution was that the barter system of trade was replaced by a system based on money and credit. Why were Arabic numerals needed to make this system work? Arabic numerals were easier for everyone to learn and use in transactions.
Arabic numerals included the number 0, which does not appear in Roman numerals.
Arabic numerals could be written in bank books without filling up the page.
Arabic numerals allowed bankers to more easily calculate the interest on a loan.

the tallest building in the western hemisphere and the sixth tallest building in the world

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.