I believe this is one of the selections that plays at the Frontierland Entrance, and is music from the Ken Burns Civil War series- not the commercially released stuff but the larger unreleased soundtrack.
That's correct-- back during the construction of Disneyland Paris-Eddie Sotto was able to purchase the ENTIRE soundtrack to Ken Burns Civil wars series----the comercially sold cd only had about 18 or so tracks from a weeks work of music. The FULL soundtrack was used at most Disney parks in some format .
Can anyone comment on why this particular track was included in the 50th Anniversary box set? I fully understand DC-88's answer regarding Disney's purchase of the larger body of work but for music from this 2002 series to be included there must be a story somewhere. Was it the short track length? Is it a homage by Randy?
When I was at Disneyland about a month ago I heard it playing from the left stockade building. That was the first time I even noticed music in that area, believe it or not, and I specifically remember "Battle Cry of Freedom".