At the last meeting of the Family History Group that I attend one member brought a Poll Book. Most people had never seen one. They were produced between the late 1600s and the late 1800s. They contained lists of all the people who had voted in a particular election with their address and, what is more, how they voted. In order to have your name recorded in a poll book, and of course able to vote, you had to own either a house or a piece of land, and you had to have actually voted.
Most clan members that we have come across were tenants and not owners. However two men did vote and were listed in the Belfast Poll Book of 1868, so must have owned the property where they lived. This book probably records the by-election on 22 November 1866 when Hugh Cairns, Conservative, resigned as Lord Justice of Appeal of England and Wales. He was replaced by Charles Lanyon, Conservative. George M'Ilhaggo of 24 Kilarney Street, Belfast, voted in Ann's Ward and Nathaniel M'Ilhaggo of 3 Meadow Street voted in Dock Ward. As yet I do not know for which party each cast their vote.