Robert Henderson b1819 East Lothian.

[Cockneyrebel]

I am looking for:
Robert Henderson 26 Dec 1819 in Moreham, East Lothian, married Marjorie Dewar Strachan 15 Jan 1861 in Dundee, Angus. They had 3 children per IGI as aghadowey also found:
Joseph Gibson (born 10 Jan.1862 Arbroath), David Dewar (born 23 Apr.1863 Arbroath) and George Alexander (born 18 Dec.1867 Arbroath).
As these were born in the 1860s, I find it strange that none of them appear on the 1871/81 Scottish census nor their parents!
Robert's sister Elisabeth b 11 Jan 1817 was living with the newly weds at the 1861 Scottish census.
Maybe the whole lot emigrated?
I'm going to post to other emigration boards to see if anything will turn up.