James Barbour was born in Dunscore. Around 1848 he was articled to Walter Newall in Dumfries. In 1860 he set up his own practice in Dumfries, and was later briefly in partnership with James Halliday in Edinburgh.
Please see the Dictionary of Scottish Architects for further details http://www.scottisharchitects.org.uk/architect_full.php?id=200331