The song identified above by Weasel is not the more common Alabama shanty, Roll Alabama Roll as suggested above. "The Alabama" by E. King was recorded, sung by Jeff Davis and very nicely too, on the CD "Civil War Navy Songs" produced by Dan Milner.

Info and sound samples here:

http://www.folkways.si.edu/dan-milner-david-coffin-jeff-davis/civil-war-naval-songs/american-folk-american-history-historical/music/album/smithsonian

(I tried to make a blue clicky, but the url is too long.)

As far as who sang it at Liverpool I have no idea. I don't think Dan Milner would be seen dead wearing a straw hat, or playing a banjo. But Bob Conroy certainly does play banjo. And they toured together in England several times, and did perform at maritime festivals. I've never heard of the 97th Regimental String Band ever being in England, but that doesn't mean much.

You could ask Dan Directly: He is "Liam's brother" on Mudcat.