This volume attempts to identify many of the Irish soldiers in the British colonies in North America and the Caribbean from around 1650 until 1825. Before 1800 Ireland was garrisoned mainly by British regiments, through new regiments were raised in Ireland, such as the Royal Regiment of Foot of Ireland and the Inniskilling Regiment.

Irish settlers in colonial America were recruited into local militias, such as the Virginia Regimnet or the Montserrat Militia, which are identified in this book. During the American Revolution, people of Irish origin could be found in both Loyalist and Patriot units, including the "Volunteers of Ireland". The Loyalist Claims reports identify Irish fighting men in the Revolution.

Between 1789 and 1815 Britain was at war with Napoleon's France, necessitating an expansion of the British Army. In the aftermath of the Battle of Waterloo the British government settled substantial numbers of demobilized soldiers, including Irishmen, in Canada. From about 1780 onwards the British regiments enlisted at least one-third of their recruits in Ireland; this increased to about 40% by the early 19th century owing to demand from the British Army and the East India Company.