Following in his father’s footsteps, Mortensen became a tailor. In 1903, in hopes of finding more job opportunities, he migrated to the United States and lived in various areas, and worked in various trades including as a milkman and in a canning factory. His job as a milkman required him to wake up at 1:30 AM, and drive a horse-drawn carriage from house to house to deliver the milk. In Denmark, Mortensen had worked as a farmhand and apprenticed as a tailor. He was married, though only briefly, and never had children. As an avid sailor, he enjoyed making sailing trips from Texas to Florida. However, in 1962, when he was 79 years old and living in Texas, Hurricane Carla destroyed his boat, leading to him making the decision to once again return to Denmark for the first time in nearly 60 years. Upon returning, he reconnected with some family members he had lost contact with, and was interviewed in a local Skanderborg newspaper, where the 79-year old Mortensen was quoted as saying, “where I hang my hat is my home. I have my carriage and rent a few rooms and a kitchen where I arrive. I manage the cooking myself, and since no one loves me, I have neither family nor home.”