Halvor Niels Christensen was born October 24, 1915, in Cozad, Nebraska to Niels and Matena Christensen. He was the third of six children. Christensen attended the Nebraska State Teacher's College and earned a Bachelor's degree in chemistry in 1935. In 1937, he obtained his Master's in biochemistry from Purdue University, and earned his PhD in biochemistry from Harvard University in 1939.
His academic professional career began at Harvard Medical School (1942-1948), first as an instructor, and then as assistant professor in biochemistry. Christensen taught at Tufts University School of Medicine as a professor and chair of its Biochemistry Department from 1949 to 1955. He then moved to the University of Michigan where he spent the majority of his career. He was a professor (1955-1986) and chair (1955-1970) of the Department of Biological Chemistry. He retired in 1986 and was named professor emeritus. Christensen moved to La Jolla, California where he served as an adjunct professor in pediatrics at the University of California in San Diego from 1989 to 1999.
Christensen was an internationally known authority in the area of amino acid transport. He was the author of a number of books in the field of biochemistry and over 270 journal articles.
He remained active in his field well into his retirement. Christensen died on October 2, 2003, at the age of 88. He was survived by his three children, Hugh, Carl and Karen. His wife Mary died in 2003.
From the guide to the Halvor N. Christensen papers, 1939-1997, 1972-1995, (Bentley Historical Library, University of Michigan)
