In 1885, Buen was among the founders of the association
Socialdemokratisk Forening. and Buen was hired there as a journalist. The name was changed from
Vort Arbeide to
Social-Demokraten ('The Social Democrat') in 1886. Buen became party secretary as well. He also chaired his local trade union from 1897 to 1898, and served one term in Kristiania city council from 1901 to 1903. In 1903, a conflict in the party forced the retreat of Buen as editor-in-chief. He was also replaced as party secretary. Instead, he was sent to
Trondhjem to edit the party organ in that city,
Ny Tid. He served as a member of Trondhjem city council from 1907 to 1910 and from 1913 to his death. He was also elected to the first session of the
Norwegian Parliament in
1906,
1909,
1912,
1915 and
1918, representing the
single-member constituency of
Lademoen. He led the Labour Party parliamentary group from 1913 to 1921, and from 1919 to 1921 he served as
President of the Storting. In the meantime, Buen had been succeeded as editor of
Ny Tid by
Martin Tranmæl. Tranmæl belonged to the radical wing of the Labour Party, and in 1921, the moderate wing broke out to form the
Social Democratic Labour Party of Norway, due to disagreements over the Labour Party's membership in the
Comintern and adaption of the
Twenty-one Conditions. Buen, described as a "
reformist pragmatic", joined the Social Democratic Labour Party. From 1922 to 1927 he edited the newspaper
Trøndelag Social-Demokrat, which can be considered an offshoot of
Ny Tid. Labour Party had officially scrapped the Twenty-one Conditions in 1923, and in 1927 the Labour Party and the Social Democratic Labour Party reconciled and reunited.
Trøndelag Social-Demokrat was disestablished, but since
Ny Tid had been usurped when the
Communist Party of Norway broke away from the Labour Party in 1923, the Labour Party organ in Trondhjem was now
Arbeider-Avisen. Buen worked as a journalist here for a few years. He also managed the local branch of
Norges Bank from 1916 to his death in 1933 and had been a member of the board of the
Norwegian Water Resources and Energy Directorate from 1921 to 1923. ==References==