Simplify the following text for a Grade 10 native English-speaking person.
Original: David Livingstone ( 19 March 1813 -- 1 May 1873 ) was a Scottish Congregationalist pioneer medical missionary with the London Missionary Society and explorer in Africa .
Simplified: David Livingstone ( March 19 , 1813 â `` May 4 , 1873 ) was a Scottish medical missionary with the London Missionary Society .