Stejneger was born in Bergen, Norway. His father was Peter Stamer Steineger, a merchant and auditor; his mother was Ingeborg Catharine. Leonhard was the eldest of seven children. His sister Agnes Steineger was a Norwegian artist. Until 1880, the Steineger family had been one of the wealthy families in Bergen; at that time business reverses led to the father declaring bankruptcy. Stejneger attended the Smith Theological School in Bergen from 1859–1860, and Bergen Latin School until 1869. His interests in zoology developed early. By age sixteen he had a printed catalogue of birds, and he painted birds in water color. He moved with his mother to Meran in South Tyrol and studied under a private tutor. Around 1870 he began to spell his surname "Stejneger" and continued to use that spelling for the rest of his life. He studied law and philosophy at the University of Christiania. He earned a Ph.D. and started a brief career as a lawyer.
Career
In 1880 Stejneger ordered a walking cane with a built-in collector's gun which would serve him in his specimen collection till the end of his life. In 1881 Stejneger moved to the United States on the advice of Jean Cabanis. He had married Anna Norman in 1876 but she chose not to move to the United States and they separated and later divorced. On arriving in the US, he immediately went to the Smithsonian Institution to meet Spencer Fullerton Baird after taking some time sitting in a park to brush up on his English vocabulary. Baird had been in communication and knew his competence and he began to work soon after. Stejneger became an American citizen in 1887. Stejneger participated in numerous expeditions to the northern parts of the North American continent. From 1882 to 1883 he was on an exploration mission to Bering Island and Kamchatka. In 1895 he went to the Commander Islands, studying fur seals for the U.S. Fish Commission. He returned there a second time in 1922. Within the Smithsonian Institution, he moved up the career ladder. In 1884 he was Assistant Curator for birds, in 1889 Curator for reptiles, in 1899 Curator for reptiles and amphibians, and from 1911 on Head Curator for biology, a post he held until his death, having been exempted from retirement by a presidential decree. Stejneger published more than 400 scientific works on birds, reptiles, seals, the herpetology of Puerto Rico, and other topics. During his Bering Island trip he became fascinated by the life of Georg Wilhelm Steller, an 18th-century naturalist who had previously visited there. He thoroughly researched Steller's life over the next few decades, a hobby which culminated in his only non-scientific publication, an authoritative Steller biography published in 1936. Stejneger was a Life Member of the Bergen Museum. He attended the International Congresses of Zoology of 1898, 1901, 1904, 1907, 1913, 1927, and 1930, as well as ornithological and fisheries congresses. He was elected to the International Committee on Zoological Nomenclature in 1898 and served as the organizing secretary for the Section on Zoogeography at the 1907 International Zoological Congress in Boston. In 1900 he was awarded a gold medal at the Paris Exposition for his work on fur seals management and conservation. In 1923 Stejneger was elected to the National Academy of Sciences. In 1931 he was made honorary president for life of the American Society of Ichthyologists and Herpetologists. In 1906 he was made knight of the Royal Norwegian Order of St. Olaf and then in 1939 Commander of the same order.
