It was powerful, at the time abolition was happening in England, people over here weren't considered people, the ones that declared independence had a slavery clause, there was nothing about the declaration which was "powerful" especially considering that it was because they revolted when people were most desperate, it was something of a natural movement, and the slave owners managed to land in the pockets they were trying to get away from. I don't know what they dreamed, but what it accomplished wasn't anything praise worthy, it led to the largest ethnic cleansing under the name Manifest Destiny while the country has been in a perpetual cannibalization ever since.