The reasons for African colonisation were mainly economic, political and religious. During this time of colonisation, an economic depression was occurring in Europe, and powerful countries such as Germany, France, and Great Britain, were losing money.
They wanted to improve their economy for instance by acquiring more spices, gold, and better and faster trading routes. Also, they really believed in the need to spread their religion, Christianity.
The tea act allowed merchants to ship goods directly to colonists instead of having to first stop in england and find merchents there to sell to the colonists.