You can easily find all this online. Do some research for any more.
The history of Sierra Leone began when the lands became inhabited by indigenous African peoples at least 2,500 years ago. Sierra Leone has played a significant part in modern African political liberty and nationalism, and became independent of the United Kingdom in 1961.
The Afro-European colony was founded by a British organization for freed American slaves on March 11, 1792. These were about 1200 Black Loyalists who had relocated from Nova Scotia after being resettled in freedom by Great Britain following the American Revolutionary War. The residents, including women, voted that year for the first time in elections for their officers.[1] Later other liberated slaves were also settled at Freetown. The people in this area developed as an ethnic group known as Krios, always a minority in the territory, which was dominated by the Temne and Mende peoples, together with several minority groups