He notably represented Wells in the House of Commons as a Conservative.
Major notably represented Scarborough in the House of Commons.
He notably represented Weymouth in the House of Commons.
He notably represented Doneraile in the Irish Parliament from 1761 to 1776.
He notably represented Lismore in the Irish House of Commons.
He notably represented Kilmarnock in Parliament as a Liberal.
He has also reopened his private law practice, notably representing Warner Pacific College.
Chapman notably represented Fore and Westmeath in the Irish House of Commons.
He notably represented Heytesbury in Parliament.
He notably represented King's Lynn in Parliament.