Complex sentence: Their eldest daughter Jane Johnston married the American ethnographer Henry Rowe Schoolcraft in 1823, who became noted for his work on the Ojibwe, aided by Jane's access and her knowledge of the language and culture.
Split into simpler sentences: Their eldest daughter Jane Johnston married the American ethnographer Henry Rowe Schoolcraft in 1823. He became noted for his work on the Ojibwe, aided by Jane's access and her knowledge of the language and culture.