The N.E. Hansen papers represent a comprehensive archive chronicling the career of Niels Ebbesen Hansen. The collection encompasses a diverse range of materials, including authored articles, bulletins, and circulars from Hansen's tenure at the South Dakota Experiment Station, as well as field notebooks, and ledgers from the South Dakota Horticultural Society.

Contributions from Helen Hansen Loen, Hansen's granddaughter, further enrich the collection with addresses, correspondence, journals, and travel documents, offering a deeper understanding of his professional and personal life. Notable highlights include addresses delivered by Hansen at prestigious events like the International Congress of Genetics in Berlin, underscoring his scholarly impact.

The collection's breadth extends to reports on forestry, sheep, and forage crops, reflecting Hansen's diverse interests. Manuscripts delve into topics ranging from agricultural practices to fine arts, while photographs document Hansen's expeditions to Siberia and Northern China, providing visual context to his exploratory work. Of particular significance are Hansen's manuscripts examining Soviet Russia's socio-political and economic landscape from 1934 to 1937. These writings offer valuable insights into agricultural collectivization, industrialization, and societal dynamics during that period, complementing Hansen's broader contributions to agricultural science.

Aceraceae Neck. Acer Ginnala Max. Plant specimen from the maple family collected by N.E. Hansen, 1924. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label printed in Russian in Cyrillic letter with hand-written notation in black ink.

Aceraceae Neck. Acer Mairunduense ? et Mey.. Plant specimen from the maple family collected by N.E. Hansen, 1924. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label printed in Russian in Cyrillic letter with hand-written notation in black ink.

Aceraceae Neck. Acer Mons Max. Plant specimen from the maple family collected by N.E. Hansen, 1924. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label printed in Russian in Cyrillic letter with hand-written notation in black ink.

Aceraceae Neck. Acer Tomentosum Max. Plant specimen from the maple family collected by N.E. Hansen, 1924. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label printed in Russian in Cyrillic letter with hand-written notation in black ink.

Caprifoliaceae Vent. Lonicera edulis Turcr. Plant specimen from the honeysuckle family collected by N.E. Hansen, 1924. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label printed in Russian in Cyrillic letter with hand-written notation in black ink.

Caprifoliaceae Vent. Lonicera Maacki Turcr. Plant specimen from the honeysuckle family collected by N.E. Hansen, 1924. This plant is native to temperate western Asia, specifically in northern and western China south to Yunnan, Mongolia, Primorsky Krai in southeastern Russia, Korea, and, albeit rare there, central and northern Honshu, Japan. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants.

Pinus pungens, also called Table Mountain Pine, hickory pine, prickly pine or mountain pine. This small pine is native to the Appalachian Mountains in the United States. Plant specimen collected by C.S. Sargent, 1912, first director of the Arnold Arboretum, Herbarium of Iowa College of Agriculture and Mechanic Arts, Ames, Iowa. N.E. Hansen graduated from Iowa State College with a bachelor's degree in horticulture in 1887. It is likely Hansen obtained this specimen during his time at the college. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label with hand-written notation in pencil ink.

Primulaceae Vent. Primula. Plant specimen collected by N.E. Hansen, 1924. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants.

Prunus persica. Dbl. fl. Peach. Kaises VII. Plant specimen collected by N.E. Hansen, 1924. The peach (Prunus persica) is a deciduous tree native to the region of Northwest China between the Tarim Basin and the north slopes of the Kunlun Shan mountains, where it was first domesticated and cultivated. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label with hand-written notation in pencil ink.

Rosaceae B. Juss. Micromeles alnifolia Koehne. Plant specimen collected by N.E. Hansen, 1924. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label printed in Russian in Cyrillic letter with hand-written notation in blank ink.

Rosaceae B. Juss. Prunus padus L. Plant specimen collected by N.E. Hansen, 1924, also known as bird cherry, hackberry, hagberry, or Mayday tree, is a species of cherry, native to norther Europe and northern Asia. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label with hand-written notation in pencil ink.

Rosaceae B. Juss. Pyrus ussuriensis Max +P. Sinensis Lindl. Plant specimen collected by N.E. Hansen, 1924, also known as the Ussurian pear, Harbin pear, and Manchurian pear, is a species of flowering plant in the family Rosaceae. It is native to Korea, Japan, and the Ussuri River area of far eastern Russia. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label printed in Russian in Cyrillic letter with hand-written notation in blank ink.

Rosaceae B. Juss. Spirea Chamaedrifolia L. Common name germander meadowsweet or elm-leaved spirea. Plant specimen collected by N.E. Hansen, 1924. Spiraea chamaedryfolia is a shrub reaching a height of 1–1.5 meters (3 feet 3 inches–4 feet 11 inches). Branchlets are brownish or red-brown. Leaves are simple, oblong or lance-shaped, toothed on the edges, 40–60 millimeters (1.6–2.4 inches) long and 10–30 millimeters (0.39–1.18 inches) wide, with a petiole of 4–7 millimeters. The white flowers of 6–9 millimeters in diameter grow in spike-like clusters at the ends of the branches. Flowering period extends from May to September. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label printed in Russian in Cyrillic letter with hand-written notation in black ink.

Rosaceae B. Juss. Spirea Chamaedrifolia L. Common name germander meadowsweet or elm-leaved spirea. Plant specimen collected by N.E. Hansen, 1924. Spiraea chamaedryfolia is a shrub reaching a height of 1–1.5 meters (3 feet 3 inches–4 feet 11 inches). Branchlets are brownish or red-brown. Leaves are simple, oblong or lance-shaped, toothed on the edges, 40–60 millimeters (1.6-2.4 inches) long and 10-30 millimeters (0.39-1.18 inches) wide, with a petiole of 4-7 millimeters. The white flowers of 6-9 millimeters in diameter grow in spike-like clusters at the ends of the branches. Flowering period extends from May to September. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label printed in Russian in Cyrillic letter with hand-written notation in black ink.

Rosaceae B. Juss. Spirea media Schmidt. Plant specimen collected by N.E. Hansen, 1924. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label printed in Russian in Cyrillic letter with hand-written notation in blank ink.

Saxifragaceae Dumort. Deutzia parviflora Bunge. Plant specimen collected by N.E. Hansen, 1924. Saxifragaceae are found mostly in the Northern Hemisphere, with centers of diversity in the Himalayas, East Asia, and Western North America. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label printed in Russian in Cyrillic letter with hand-written notation in blank ink.

Saxofragaceae Dumort. Ribes manshuricum (Max.) Kom. Plant specimen collected by N.E. Hansen, 1924. Saxifragaceae are found mostly in the Northern Hemisphere, with centers of diversity in the Himalayas, East Asia, and Western North America. N.E. Hansen (1866-1950) was a Danish-American horticulturist and botanist who was a pioneer in plant breeding. Hansen came to South Dakota in 1895 and became the first head of the Horticultural Department of South Dakota State College. He also served as agricultural explorer for the United States Department of Agriculture. He searched for hardy grasses, fruits, and other plants throughout Europe and Asia and brought them back to the United States to raise or crossbreed with American varieties to produce hardy plants. Specimen is mounted on an 11.5 x 16.5 inch herbarium sheet accompanied by a label printed in Russian in Cyrillic letter with hand-written notation in black ink.