The O'Carrolls are an ancient family that can trace their roots in the early history of Ireland. But in less ancient times(!) Teige O'Carroll defeated the forces of King Richard II which had invaded the Kingdom of Ely O'Carroll in 1395. The O'Carrolls had withstood the most powerful of armies of the time and repelled them. But by 1590 the O'Carrolls had lost most of their power and by the Cromwellian confiscations, most of their territory. So by 1690 the O'Carrolls fought at the Battle of the Boyne in a desparate bid to regain independence for Ireland.
My website includes information about the descendants of Col.Thomas O'Carroll. He fought and died at the Battle of the Boyne leaving two young sons. He was the brother of Charles Carroll who emigrated to Maryland in 1688, the grandfather of Charles Carroll of Carrollton who signed the American Declaration of Independence. The orphaned boys were removed from their hearth to families far away. One was to become a farmer in Moira the other we know not where. This boy prospered, married and had many children. By the end of the eighteenth century some of his 10 grandchildren had moved to Cork and in 1800 Edward, who had inherited the homestead sold up to a neighbour and emigrated to the USA settling in East Liverpool, in what is now Ohio in 1801. The family in Cork moved to England at the end of the nineteenth century.