Dumfries was a royal burgh that returned one commissioner to the Parliament of Scotland and to the Convention of Estates.
After the Acts of Union 1707, Dumfries, Annan, Kirkcudbright, Lochmaben and Sanquhar formed the Dumfries district of burghs, returning one member between them to the House of Commons of Great Britain.
References
Dumfries (Parliament of Scotland constituency) Wikipedia(Text) CC BY-SA