Leif Jenssen was born in 1880 in Norway and immigrated to the U.S. in 1904. From 1913 to 1923 Jenssen was in partnership with Frederick German. This firm is best known for designing the Pilgrim Congregational Church. Jenssen gained his citizenship in 1917. In 1921 he joined four other men (including Frederick German) in incorporating the Duluth Holding Company, formed to deal in properties, buildings and improvements. His 1923 obituary documents his sudden death at a young age:
DEATH TAKES LIEF JENSSEN, LEADING LOCAL ARCHITECT. Lief (sic) Jenssen, aged 39, of the firm of German & Jenssen, architects and engineers, died suddenly during the night at his home, 2006 Crescent View avenue, from a hemorrhage of the brain. Mr. Jenssen was apparently in the best of health throughout yesterday while at his offices, his partner, Mr. German, said today. He spent the evening with his family and retired without complaining of illness. During the night Mrs. Jenssen heard her husband groan and investigating, found him twisting in pain. She immediately telephoned Dr. W. A. Coventry but Mr. Jenssen was dead when she returned to his bedside. Mr. Jenssen was born in Norway where he was graduated from the Norway university and also from a German university. He came to this country about twenty-two years ago, settling in Chicago, where he took a post-graduate university course. About eighteen years ago he became associated with Mr. German. He had been prominent in designing and supervising the construction of a number of leading buildings in the Northwest, besides residences. The firm designed and constructed the Marshall-Wells plant, were supervising the work on a new school in Chisholm, Minn., and a Masonic temple and city hall at Virginia, Minn., besides a number of other public and private buildings. Recently they received a contract from the Duluth board of education for the construction of a school. The firm also designed the proposed new city hall for Duluth and were to supervise its construction [this never occurred as a design competition was held at a later date]. Lakeside Masonic lodge, of which Mr. Jenssen was a member, will have charge of the funeral, arrangements for which will be completed tomorrow. He is survived by his wife and three children, two boys and a girl, and relatives in Norway…
Leif Jennsen, a highly qualified architect who has practiced his profession in Duluth some ten years. is a member of the firm German & Jenssen, whose professional work is exemplified in many of the outstanding public structures of Duluth and vicinity.
Mr. Jenssen was born in Norway February 16, 1879. He was liberally educated in his native country and graduated from the Norwegian Polytechnic Institute. He came to America alone in 1901 and for a time was employed as a draftsman in New York city. In 1903 he removed to Chicago and was similarly engaged there until he came to Duluth in 1909. During the following four years he was in the offices of the architectural firm German & Lignell. When that firm was dissolved in 1913 Mr. Jenssen became associated with Mr. German under the firm name of German & Jenssen, architects, whose offices are in the Exchange Building.
During the past five or six years they have had a large share of the architectural work of the city and have drawn plans and supervised construction for many prominent residences and business and public buildings.
Some of the public structures for which they have been architects are the Washington Manual Training School, Superior High School, the Lincoln School, the Young Men’s Christian Association and Young Women’s Christian Association Buildings and many beautiful residences.
Mr. Jenssen is a member of the American Institute of Architects. and belongs to the Duluth Engineers’ Club and the Architects’ Association of Manitoba. In 1907 he married Miss Larsen, whose people also came from Norway. They are the parents of three children.