During the great famine in Ireland in the middle of the 19th century, many Irish people immigrated to America. Sean O'Kelley, born 1839, was one of them. He was only 8 years old when he and his family emigrated from somewhere around Cobh, Ireland, to Michigan in USA. Sean O'Kelley is the great-grandfather of the "The Kelly Family". In USA, they changed the name O'Kelley to Kelly, to sound more American.