Ashokan Farewell - from Ken Burns, The Civil War series.

This one may be hard to obtain due to the pertinent included monologue is not available on the soundtrack.

https://www.youtube.com/watch?v=uZmxZThb084

However, if you have the patience you can listen to two narratives with the song in the background @

https://www.youtube.com/watch?v=Y7HmBmWz9mI

https://www.youtube.com/watch?v=1VK1KcZoDu0