"Here's a Health to the Company" is an Irish traditional song, based on the long history of emigration from Scotland and Ireland.
Robin Morton lists it in Folksongs Sung in Ulster,[1] and Paddy Tunney learned the song from North Antrim singer Joe Holmes.
[2] It is markedly similar to the Aberdeenshire song known as "The Emigrant's Farewell To Donside".
Hugh Shields writes: "The song is quite well known in the northern counties of Ireland, and with varying text, it has been noted in Canada and Scotland, where it was perhaps composed.
"[3] The use of the tune by the eighteenth-century American Liberty Song could reflect an association with Ulster Scots tradition, as most early Irish emigrants came from this community.