korrektur englisch text (triangular trade)

Triangular trade: Fortunately slavery almost has been banned in our time.
However, in former days it was ordinary to sell and to buy black people. Slaves were not paid and had to do all sorts of jobs for their owner. They  performed heavy work particularly on plantations for example like picking cotton, harvesting tabacco, rice, sugar  and coffe but also cooking was the work of the slave. So they  were treated by the farmers like machines. In old civilizations slavery was very common and also the triangular trade was very popular for the countries: Portugal, Great Britain, the Netherlands, France, Spain, Denmark and Sweden. But America was the main representative of this trade. The triangular trade ent about 350 to 400 years. It began in 1680 and ended in 1807 by forbade of the english slave trade. However, the trad was still carried out in the different countries of America. Within the almost 400 years of the atlantic slavery about 10 to 12 million slaves were brought to the Caribbean on the Islands, 3.5 to 5 million reached Bazil and a half million of slaves were sold to the USA.
So a commerce developed from Europe, West Africa and the Caribbean in the triangle. In october the European great powers equipped ships, loaded with textiles, rum and manufactured goods. The ships sailed to the West Africain coasts where the goods were exchanged for slaves. The slaves were bought at slave markets from local traders. Afterwards at the beginning of december the ships which were loaded with slaves sailed to America where they were sold at the highest possible prices. Then the ships were loaded again but this time with the popular goods from the Caribbean and America like for example: tea, coffee, sugar, cotton, tabacco, spices and so on. From april the ships sailed again back to Europe to sell there the goods on the european market.