Islam brought upon a new period of economic success to West Africa. They were able to expand their gold trade to surround Arab nations through mutual grounds that the adoption of Islam supplied them with. Initiated trade routes made a dramatic increase in the capacity of African trade possible. Trading cities appeared throughout West Africa, raising the population to around 100,000. Merchants also introduced different useful goods such as rice, citrus fruits, and cotton to West Africa, resulting in cotton to be the leading material made during the 16th Century. It could easily be made certain that West Africa would persist to be economically successful, thanks to the European demand for cotton. As well, Islamic merchants greatly increased the extent of slave trade, creating large state economies revolving around the capture and sell of slaves to distant nations. Despite all of these alterations in the economy, West African states remained dependent on trade as the main structure of economic support during the times of Islamic Influence.