Complex sentence: Thomson, the youngest of six children, arrived in the United States from Scotland at age two with his family; his father, a cabinetmaker, had moved to New York shortly before Bobby's birth and sent for his family later.
Split into simpler sentences: Thomson, the youngest of six children, arrived in the United States from Scotland at age two with his family. His father, a Cabinetmaker, had moved to New York shortly before Bobby's birth and sent for his family later.