The O'Rorke, McDonald & Tweed papers consist of 632 deeds and volumes, 1630 to 1969, relating to this firm of solicitors and its clients. The archive is arranged in two different sections: the first comprises organisational files of O'Rorke, McDonald & Tweed; whereas the second comprises individual client files which are listed by family.
Since its establishment in 1839, the firm under a succession of names had offices (some of them part-time only) at various times in Ballymena, Belfast, Antrim, Larne, Crumlin, Ballyclare, Glenarm and Ballycastle. At present there are two full-time offices at 37-39 Church Street, Antrim, and at 29 The Roddens, Larne, and two one-day attendance offices at Ballyclare and Glenarm. The office at Ballyclare is attended on Tuesday morning each week and the Glenarm Office is attended on Monday afternoon each week.