In 1865 he became director-general in the Ministry of Education, while remaining one of three joint headmasters of Nissen's Girls' School until 1872.

His great-grandfather Niels Hansen Nissen was born in Fredericia in Denmark and moved to Trondheim in Norway, where he became a merchant.

In June 1843 in Christiania he married Karen Magdalena Aas (1820–1900), a granddaughter of Erik Andreas Colban.

[1] He had great influence on educational policy in Norway in the 19th century, being the architect behind several law reforms.

He was elected deputy representative for the Parliament of Norway in 1857 and in 1859, and was appointed Knight of the Order of St. Olav in 1864.