You got your centuries mixed up.
The economy of early America was built largley on the lumber trade, much needed for the growing navies of European empires who had been depleting their own forests.
London became an economic capital via banks and insurance companies involved mainly in the slave trade back in them days - companies still active today.
Slave trading in the British Empire did not exactly end in 1807, however, having continued in Australia well into the 20th Century. Indigenous populations of British colonies throughout the Americas, Africa, Asia, and, oh yes, Europe - in case you haven't heard of Ireland - were basically the property of the British Crown, and they have their more than fair share of abuses and death courtesy of the Brits than anyone would like to hear. Same goes for French, Portugese, and Spanish, etc, colonies.
There were slave uprisings in the Virgin Islands and Haiti. In the USA, not really so much.
Some owners of plantations in America became very rich. Most didn't, and most citizens did not own slaves.
Aside from those few that made it rich, the rest of the population didn't and thus slave owning States lagged economically behind the manufacturing and trading North. Slavery itself was on the way out, profitability ever waning.