It seems that the Anti-Slavery Society credits Massachusetts with abolishing slavery in their constitution (1780), as interpreted in an unrecorded court documents written by Chief Justice Cushing: http://www.anti-slaverysociety.addr.com/hus-mass.htm
I believe that slavery was still practiced in the North for many years after individual states abolished the practice.
No state abolished slavery during the Revolutionary War. Massachusetts via its Constitution of 1780 did not recognize slavery and thusly "abolished" it, but no state abolished slavery as far as I can see before or "around the time" of the Revolutionary War.
... abolish slavery.
The first of the 13 British colonies in America to abolish slavery was Rhode Island. This was done in 1774, 2 years before the American Revolution in 1776.
Equality for all men; abolish slavery.
abolitionists were basically Unionists who wanted to abolish slavery before and during the Civil War.
The certain Brazil was the last country in the Americas to abolish slavery. It would appear that documentation is required to establish a fact that the United States was the first nation in the Americas to adopt slavery. With that said, it's clear that before the United States was an independent country, slavery existed in the Americas where the British, French and Spanish ruled colonies and territories.
No, America abolished slavery in 1860, and the abolition would not havve happened if it had not been for Lincoln. 1860 was late, as Britain abolished slavery in 1807, fifty three years before the British
Give free slaves the right to vote immediately
No, it was Vermont in 1777. Vermont became a republic before becoming the 14th US state in 1791.
China officially abolished slavery in 1910 with the passage of the "Imperial Edict to Abolish All Forms of Slavery" under the Qing Dynasty. However, some forms of indentured servitude and forced labor persisted in certain regions beyond this date.
The Emancipation Proclamation signed by Abraham Lincoln ended slavery.
When the book was published it gave a view of slavery that hasn't been given before and caused people to discuss and think about slavery. This took place just before the start of the civil war and contributed to the discussion about how to abolish slavery.