another state joins the Union?

[JenB]

Many of these errors in family trees are due to the drop-down menus which appeared while the person was entering the data.  There is usually a US bias and it's all too easy to click on the wrong option. 

The 1861 census on Ancestry shows some 360 people, mostly living in County Durham, who were, apparently born in the Western Sahara.

It transpires that they were born in the village of Esh.

ESH is the three letter code for Western Sahara 

[HughC]

Drop-down menus?  So called because of all the clangers?

Another possibility is that they were using voice-recognition software and dictated what they read off the forms (or ledger entries, or whatever the source material is).  I don't think that works too well with proper names (persons or places), any more than a spelling checker usually does.

This is only a hunch, but some of the idiocies do have the look of dictation errors.

[Sloe Gin]

I don't keep a tree on Ancestry, but I've certainly encountered the dreaded drop-down menus when using the New Search (which is one reason why I now stick to the Old Search). 

I'd be trying to type in, say, 'Birmingham', and the menu would keep butting in with suggestions, top of which was 'Birmingham, Alabama' followed by numerous other namesakes.  'Birmingham, England' was always a fair old way down the list.  Soooo easy to let the wrong one in if you weren't very careful.    They may have changed it by now in regard to the non-US sites, but a lot of the mistakes were probably made a while ago.