There is a Glenelg, away up in the West Highlands of Scotland. ...Your document attached to your post for 1856 gives him as being born there, with his parents being
James & Elizabeth. But your public tree has him born in Glasgow to Kenneth Campbell & Catherine, and you give this marriage a question mark....

Glenelg is next to Glenelg Bay, and I have a feeling
that some early ships left Scotland from that area - but you also believe that there was a Glasgow connection, so it is unclear.
Brian, Glasgow.
P.S. It could just as easily be Glasgow they departed from, because this was the biggest shipping port in Scotland by far.