it's on a CD that I think is marvelous:

RDR 1500, A Treasury Of Library Of Congress Field Recordings, $12.98

Here are 30 of the greatest performances from the legendary Library of Congress recording series. This treasury is an extraordinary collection of America's folk voices -- a State of the Union circa 1941.

Bonaparte's Retreat ~ Rock Island Line ~ Pretty Polly ~ Pullin' the Skiff ~ Shortenin' Bread ~ Sea Lion Woman ~ Soldier's Joy ~ Another Man Done Gone ~ Northfield ~ When I Lay My Burden Down ~ Grub Springs ~ Ain't No Grave Can Hold My Body Down ~ Iron Merrimac ~ Creek Lullaby ~ Coal Creek March ~ Worried Life Blues ~ One Morning in May ~ Blood-Strained Banders ~ Goodbye, Old Paint ~ Lead Me to the Rock ~ Glory in the Meetinghouse ~ The Avondale Mine Disaster ~ Roll on the Ground ~ Diamond Joe ~ Lost John ~ Sept ans sur mer ~ East Texas Rag ~ Old Joe Clark ~ The Gypsy Davy ~ Kiowa Story of the Flute

I think the movie in question is The General's Daughter---I haven't seen it, but I'm told it features several tracks from this CD. Notably Kelly Pace's Rock Island Line.

Available, of course, from CAMSCO.