ANDERSON in Blackford

[spiritwolf]

Searching for: John Anderson born 1760?
Archibald Anderson born Feb 04,1798
Alexander Anderson born 1831

[Kingetter]

Is this your John ANDERSON

John ANDERSON

Birth: BEF 02 SEP 1758 in Blackford, Perthshire, Scotland
Christening: 02 SEP 1758 Blackford, Perthshire, Scotland

Father: Archibald ANDERSON b: ABT 1728 in Drumcairne, Tyrone, Ireland
Mother: Abigail FILP

James.

[Lesley Robertson]

Searching for: John Anderson born 1760?
Archibald Anderson born Feb 04,1798
Alexander Anderson born 1831

In your place, I'd be looking for death certificates. BMDs started in 1855 in Scotland, so you might even be lucky with Alexander's marriage certificate. Scotland's certificates are very informative (provided that the person registering the event knew the info of course).
Scottish BMDs are to be found on Scotlands People. It's a pay to use site, but not expensive. Also to be found there are the census returns. These started in 1841, you you should be lucky with Archibald and Alexander.

Of course, these are not rare names - do you have any idea of the parishes involved?