Johann (John) immigrated to the United States in 1901 with his older brother, Paul. They are both listed on the New York Passenger List, on the ship Fürst Bismark, arriving in New York on 3 May 1901, which departed on 25 April 1901 from Hamburg, Germany. John was 15 years of age, while his brother was 18. Their place of residence was Bredstedt. Their final destination was Chicago, Illinois, to the home of their uncle, Christian Ingwersen.

John's brother, Joachim (Joe), arrived in 1902, at age 14. His sister, Auguste, arrived in 1909, age 19 on the ship Pennsylvania. His father Friedrich Ludwig Carstensen followed, immigrating in 1911. His mother, Laura Henriette Ingwersen, remained in Germany. John married first, Carolyn Meyer, daughter of Johann Meyer and Anna nee Suhlsen, on 11 March 1910, in Lyon County, Iowa. They had three children:

• Irma Henrietta Carstensen, born 1911, Minnesota, married Julius Ingwersen.
• Helen Lucille Carstensen, born in 1912, in Minnesota, married Gene Ray Thompson.

(Before her marriage to Mr. Thompson, Helen had an out-of-wedlock child with Wendell Schuck, a single man. An adoption decree showed the child was named Wendell Carstensen. Upon adoption, he was given the name, Bob S. Mugge.)

• Kenneth Carstensen, was born in 1914, Minnesota. He died in 1933. Kenneth never married.

In 1910, John and Carolyn lived in Battle Plain, Rock County, Minnesota, where he was a farmer. He rented his farm. He was an English speaker. Living with them was a hired man, Pet Petersen, age 22, born circa 1888, in Iowa, from German parents.

The 1915 state census shows he lived in Waterford, Clay County, Iowa, with an Everly Postal address. He was a farmer, valuing his farm or home at $24,000. He indicates an affiliation with the Lutheran Church.

Beginning sometime in 1913, Johann had a relationship with his wife's younger sister, Isabelle Meyer. The relationship resulted in two children. The first child, a daughter, Carol Marie Meyer, was born in 1914, in Iowa. The second was a son, born in 1915, in Minnesota, who was later named William Wipperman. Isabelle died a few years later, in 1918, at age 24, reportedly from the Spanish flu pandemic at the time.

Due to the extramarital relationship, the marriage to his first wife, Carolyn ended in divorce, finalized on 30 August 1916, in Clay County, Iowa. Carolyn married her second husband, Henry Friedricksen, on 2 July 1918, in O'Brien County, Iowa.

John's WWI Draft registration card, dated 12 Sept 1918, showed his address as 1913 Farman, Omaha, Douglas, Nebraska. He was working as a bookkeeper for E. H. Andersen Company. He listed his nearest relative as Paul Carstensen, brother, of Everly, Clay County, Iowa.

The 1920 census shows John was a roomer at 2214, North 22nd Street, Omaha, Douglas, Nebraska. He was working as a salesman, selling farm implements. It notes he was divorced, with submitted naturalization papers.

John married second, on 23 November 1923, Anna Cecelia Petersen of Carroll, Wayne, Nebraska. Anna was the daughter of Boy Peter Petersen and Sophia Boysen, immigrants from Schleswig-Holstein, Germany. John and Anna settled in Klamath Falls, Oregon. They had four children, Robert (Bob), Anna, John, and Boyd.

In 1930, John and his family lived in Mount Lake, Klamath Falls, Oregon, where he was a farmer and homeowner. His home was valued at $10, 500. The record shows he was naturalized.

In 1940, the census record indicates he and his family lived on Lake Shore Drive, Orindale, Klamath Falls, Oregon. They lived at the same residence in 1935. He was working as an accountant for the lumber Industry. The value of his home was listed as $30,000.

His WWII Draft Registration, 1942, shows he was 54 years old. He lived on Lake Shore Drive, Klamath Falls, and was employed at Camp White, Medford, Oregon. Camp White was an Army training facility in Jackson County, Oregon.

Years later, John and Anna, lived in Yreka, California, where he managed a Hereford cattle ranch.

John died 24 Jan 1972, Medford, Jackson, Oregon.