Son of Rasmus Erastus Jacobsen and his wife Everine. The family crossed the Atlantic on the ship Antarctic in 1863. Evidence from Perpetual Emigrating Fund records proves they traveled on to Utah this same year. Jacob's twelve-year old sister, Ingeborg (a. k. a. Elizabeth Isabelle), who was then age twelve recalled that en-route a wagon wheel ran over their mother, severely injuring her and forcing the family to stop at Fort Laramie while the pioneer company with which they had been traveling continued on. Their father worked at the fort to obtain food for his family until they joined a later pioneer company. Ingeborg relates that Joseph F. Smith, a missionary returning from England, was also in this company [led by John W. Woolley]. According to Ingeborg her baby sister (Iverine Lorena) died and was buried three day west of Fort Laramie.