How would YOU have voted at the Constitutional Convention? Abolishing slavery would have abolished the United States. By the way, we were separate BRITISH colonies in 1619 and Britain did not abolish slavery until 1833, over 40 years AFTER our Constitution was ratified. For the US, abolishing the slave trade in 1808 was a major step in the right direction. It is too bad that competing economic and social interests prevented a peaceful resolution of this issue. Slavery was completely abolished throughout the Western Hemisphere by 1888.