Steve, have you a date for the original sheet music? Or a link?

The attribution to Harry Sydney comes four years earlier than the notice crediting it to Cavan in The Era (Feb. 22, 1863).

Digressing a bit, Civil War Veteran Robert J. Burdette recalled years later that the tune - along with "The Girl I Left Behind Me" and "Garry Owen" [sic] - was a popular fife and drum march of the 47th Illinois Infantry.

According to the African-American paper The Freeman (Indianapolis) (Aug. 27, 1898), Frederick Douglass played the tune (also "The Irish Washerwoman") expertly on the violin.

(And not forgetting a Happy New Year to British and Irish Mudcatters - from this side of the puddle.)