Dorman was born in Dublin and served with the Royal Navy in British Columbia and with the Young Men's Christian Association, later working in insurance.
Dorman proposed a long resolution which demanded manhood suffrage; the eight-hour day; promotion of trade unionism; assimilation of the borough and parliamentary franchise; labour representation in parliament and on local boards; and payment of MPs by the state.
Dorman, in calling for an eight-hour day, stressed the educative and ethical value of such a reform:[4] It gave the worker time for recreation, time for educating himself, and getting a knowledge of the world and the things that were taking place about him; and not only that but it gave the workingman who was the father of a family an opportunity for performing the duties of his position as a parent required of him.Dorman had 13 children by two different wives, all of whom lived into adulthood.
Dorman announced the formation of the Irish section of the Independent Labour Party in November 1894, at an open aired meeting in Dublin in which he spoke alongside Keir Hardie.
[12] Later in the year, he stood to succeed Joseph Davison as alderman for the Court ward on the Belfast Corporation, but he was defeated by independent Unionist John William Nixon.