Niels Ebbesen Hansen
Niels Ebbesen Hansen was born in the village of Fardrup, in Ribe County, Denmark. He was the son of Danish-born muralist Andreas Hansen and Bodil Midtgaard. His parents brought him to the United States at the age of seven. In 1876, the family moved to Des Moines, Iowa. At the age of seventeen he entered Iowa State College from which he graduated with a B.S. in horticulture in 1887. After graduation, he worked for a time in a large grape nursery. He was induced to return to Iowa State, where he was awarded his Master of Science degree in 1895.
In 1895,South Dakota State College (now South Dakota State University), appointed Hansen to build its Horticultural Department. He also served as the director of the South Dakota Experiment Station at Brookings.
Hansen searched for new grasses, fruits and other plants throughout Europe and Asia. He brought these plants back to America to raise or crossbreed with American varieties to produce a stronger plant. He was the originator of many new fruits, among them the Hansen hybrid plums. He is credited with the discovery and introduction of hardy Cossack alfalfa, crested wheat grass and brome grass. He developed larger apricots and plums by crossing native varieties with those he brought from Asia.
On an 1897 trip to Russia, he encountered the red-fleshed wild apple Malus niedzwetskyana and began two breeding programs based on this unusual fruit, one aimed at developing a cold-hardy cooking and eating apple, and the other aimed at developing ornamental crabapples. His efforts resulted in the Almata apple and the Hopa crabapple, among other varieties. When he discovered that the northwest apple breeder Albert Etter had beaten him to the punch in creating red-fleshed hybrids, he wrote to concede him priority with the words "Mr. Etter, you have defeated me in my destiny." 
Hansen was a member of the International Jury of Horticulture at the World's Fair in St. Louis, Missouri in 1904 and a United States delegate to the First International Congress of Genetics in London, England in 1906. He served as secretary of the South Dakota Horticultural Society for many years. In 1949, a monument in recognition of Dr. Hansen and his contributions was erected on the campus of South Dakota State College.
A collection of the records, faculty papers, and related materials of Niels Ebbesen Hansen are maintained in the Archives of South Dakota State University.
- Notes on the breeding of fruits (1893)
- Fruit stocks where the mercury freezes (1931)
- The wild alfalfas and clovers of Siberia, with a perspective view of the alfalfas of the world (1909)
- Some Sterile And Fertile Plant Hybrids (1926)
- Fruits, old and new and northern plant novelties (1937)
- Niels Ebbesen Hansen Papers (South Dakota State Agricultural Heritage Museum) 
- Niels Ebbesen Hansen—Pioneer Fruit Breeder (by A.F. Yeager. Journal of the American Pomological Society Volume 13 Number 2 Article 1 Year 1958) 
- Niels Ebbesen Hansen 1866-1950 17. South Dakota History. Archived from the original on 2005-09-06.
- The Life and Work of Niels Ebbesen Hansen ( from To Plant the Prairies and the Plains 1941. by Mrs. H. J. Taylor) 
- Fishman, R. "Albert Etter and the Pink-Fleshed Daughters of Surprise". CRFG Fruit Gardener May/June 1995.
- Kephart, Kevin; Lance Nixon. The Remarkable Dr. Niels Hansen. South Dakota State University.
- "Niels Ebbesen Hansen". Northscaping. Retrieved 2009-09-02.
- Pudoc (December 1986). Horticultural Research International: Directory of Horticultural Research Institutes and Their Activities in 63 Countries. Center Agricultural Pub & Document. ISBN 978-90-6605-332-8.
- Faculty Papers, N.E. Hansen papers (South Dakota State University Archives. University Collections) 
- "Author Query for 'N.E.Hansen'". International Plant Names Index.
- Rumbaugh, M. D N.E. Hansen's contributions to alfalfa breeding in North America (Bulletin / Agricultural Experiment Station, South Dakota State University. 1979)
- Loen, Helen Hansen, The banebryder (the trail breaker): The Travel Records of Niels Ebbesen Hansen, 1897-1934 (Kalamazoo, Mich.: H. Loen. 2002)
- Loen, Helen Hansen, With a Brush and Muslin Bag: the Life of Niels Ebbesen Hansen (Kalamazoo, Mich.: H. Loen. 2003)
- Loen, Helen Hansen, The Journals of Niels Ebbesen Hansen, 1879-1892 (Kalamazoo, Mich.: H. Loen. 2004)