This work is the 4th of 6 volumes outlining the Sullivan families who immigrated during the mid-19th and early 20th centuries settling in Fall River, Massachusetts and the surrounding Bristol County. The preponderance of these families left Southwest Co. Cork, Ireland and a large number specifically left the Beara Peninsula of that county. Each volume is fully indexed, and volume 6 contains an index for all 6 volumes. The use of U.S. census records, county vital records, personal letters, obituaries, newspaper stories and the Irish parish records allowed more than 12,000 individual Sullivans to be assembled into family groups, and their family lines traced to their home country. The struggles of these families to establish themselves in America come to life as the reader follows the lives and achievements of this prolific family.