He was a Scottish doctor and was the first to explore the African interior. He attempted it twice. The first one was in 1795. He saw the River Niger and went back to England to report his findings.
Nine to ten years later, he embarked on the second journey; i.e. 1805, this time with forty-four people in his team and they sailed down the Niger.
Unfortunately, none of them survived except a slave who told their story. Most of them died of tropical diseases while others like Mungo Park died in a boat accident.