In 1833, the Parliament of UK abolished slavery throughout most of the British Empire. However, plantation owners had already figured out a new way of exploitation.

As soon as slavery ended, the British introduced a system of indentured servitude. Under this system, upto 3.5 million* Indians, most of them illiterate peasants, were transported to British colonies in Africa, Guyana, Fiji, etc. over the next 90 years

These indentured laborers, derogatorily labelled ‘Coolies’, worked on the plantations, replacing the freed slaves. Their conditions were no different than slavery. These are the words of the very last surviving witness of this system in Guyana. She talks in a pidgin of English and something else.

Link to original documentary, "How the British Re-invented Slavery" -    • Coolies: How Britain Re-Invented Slavery  

* 3.5 million is the figure I got from Wikipedia. The documentary itself presents a figure of 1 million. Estimates seem to vary a lot.