What product brought British colonists to Nigeria in the late 1800s?

Palm Oil

Explanation:

British colonists began to take interest in Nigeria during the late 1800s because of the emergence of palm oil industries in the Niger Delta of Nigeria. The emergence of export for palm oil from Nigeria threatened the world market, led the British to act and introduce policies to control the production of oil. Palm oil production became important in the late 1800s after the abolition of the slave trade.

Ivory and all the other minerals that lay in the land but also man power (slaves).