Britain in this period was going through a vital economic shift from still being a largely based agricultural country to one increasingly dominated by manufacturing. The needs of British manufacturers unquestionably contributed significantly to the expansion of the slave trade in the years 1760-1800s. However, other factors including the profit made form the slave trade, the markets created for British manufactured goods, consumer demand of slave made products and the efficiency of the slave trade itself all contributed to the expansion of the slave trade.
British manufacturers drove the expansion of the slave trade because slave traders needed the products they made such as pots, silk and guns to trade with the West Africans for slaves, “These goods would then be traded for enslaved Africans. Birmingham had over 4000 gun-makers, with 100,000 guns a year going to slave-traders”; this quote shows that Britain’s manufacturers made thousands of guns to help boost the amount of slaves being captured and sold.
Also British manufactures increased the demand for slaves by plantation owners meaning more products had to be made in order to keep up with the number of slaves being captured; this helped sustain their trade with the West Africans suggesting that Britain was dominant in the slave trade. “There were profits for England at every point in the triangle”, this signifying that Britain shaped the slave trade and helped in to expand in order to maintain Britain’s economy and empire.
Nonetheless, another factor which led to the expansion of the trade was Britain’s demand for products made by slaves, this included sugar, tobacco and cotton; “The British consumption of slave-grown produce increased remarkably in the eighteenth century. ” British consumers became addicted to sugar and smoking on a lavish scale. Their smoking habit and taste for sugar was sustained as these products were grown on British colonies such as Barbados and Jamaica and harvested by enslaved Africans.
Over the years the demand for slave made products increased massively, “Thus between 1748 and 1776 sugar imports doubled from 900,000 to 1. 8 million. ” Thousands of tons of sugar was imported to Britain which increased the amount of slaves having to work and harvest it meaning that the slave trade would have to work continuously as some enslaved Africans would die or get sick so more Africans had to be traded and sold to the West Indies to work as slaves on sugar and other plantations.
At first sugar and other rare products made form the West Indies was extremely expensive, but as the trade expanded the price of sugar dropped meaning it was more easily accessible by poorer commuters in Britain. Profits were made in many other areas of the slave trade which led to its expansion, the profits made from building ships and any other areas that were involved with the manufacturing of ships increase greatly as materials, like wood, were needed to build slave ships which were used to carry slaves to America and bring slave made products back to Britain to be sold.
It is crucial to mention the efficiency of the slave trade itself when discussing the expansion of the slave trade. The trade was so efficient simply because the slave ships were literally compacted until every space was filled.  The ships would travel to Africa full of British products to trade with the Africans in exchange for slaves which would be packed on to the ships as cargo, chattel slaves, and then they would be taken to the West Indies and finally would make its journey back to Britain and be full of slave made produce ready to be sold.
This expanded the slave trade itself as not a single journey taken by the slave traders were wasted; every nook and cranny of the ships were filled with cargo, ensuring that the most profit would be made from it. Additionally, another factor which expanded the slave trade in the year 1760-1800s was the markets created for British manufactured goods. Bristol and Liverpool became leading ports for making slave ships and handing the cargo they brought back from the West Indies.
When Liverpool replaced Bristol as the leading British port for the slave trade, it became the major port in manufacturing glass, copper and brassware. Glass was made in to beads which were sometimes made into necklaces or bracelets and then traded for slaves; these slaves were then traded for bottles in the British colonies in the West Indies. As Liverpool became the major port for the slave trade the population grew rapidly due to its new found prosperity “Between 1700 and 1800, Liverpool’s population rose from 5000 to 78,000. 
Moreover Manchester became the centre in making cotton cloth and Birmingham flourished in manufacturing metal things like chains and padlocks. In conclusion, I believe that although the need for British manufacturers did drive the expansion of the slave trade in 1760-1800s rather significantly but there were more influential factors that contributed in expanding the slave trade, especially the demand for slave made products. This helped drive the expansion of the slave trade because it helped expand British colonies in the West Indies and it established the requirements of the mercantile trade and ship owners.
However, many people could argue that the profits made by the slave trade weren’t very consistent. Furthermore we’re not sure whether the profits were actually invested in the industrial revolution. Only a few plantation owners invested their money in to new factories and inventions, helping to finance the industrial revolution, but it’s more likely that plantation owner’s and merchants spent their profits on buying land or building grand country houses for themselves.