In 1966, Sinclair and fellow lecturer Bob Chapman established The University of Auckland Art Collection, beginning with the purchase of several paintings and drawings by Colin McCahon. The Collection is now managed by the Centre for Art Research, based at the Gus Fisher Gallery.
Sinclair won widespread acclaim for his first book of history, The Origins of the Maori Wars (1957). His next book, A History of New Zealand (1959), is often regarded as a classic in New Zealand history. The book remains in print, being revised several times, the last, with additions by fellow academic Raewyn Dalziel, in 2000. In 1967 he founded the New Zealand Journal of History.
In both his poetry and his work as a historian, Sinclair was a nationalist, in the sense that he was concerned with forging a national identity for New Zealand that was independent of its colonial origins.[3]
In the 1969 general election he was the Labour Party candidate for Eden. He won the electorate on the night, but was defeated 3 weeks later on the final count (including special votes) by only 67 votes.[5]<[6] Later he wrote an acclaimed biography of Labour Prime Minister Walter Nash who had left his vast personal archives at Sinclair's disposal. The book won the 1977 National Book Award.[3]
In 2003, the University of Auckland established the Keith Sinclair Chair in History in his honour. In 2005, he was named one of New Zealand's Top 100 History Makers.
One of his sons is the actor Harry Sinclair; another, Stephen, is a New Zealand playwright and poet.
^Sinclair, Keith (1946). The aborigines protection society and New Zealand: A study in nineteenth century opinion (Masters thesis). ResearchSpace@Auckland, University of Auckland. hdl:2292/19200.
^Norton, Clifford (1988). New Zealand Parliamentary Election Results 1946–1987: Occasional Publications No 1, Department of Political Science. Wellington: Victoria University of Wellington. p. 220. ISBN0-475-11200-8.
^ abSinclair, Keith (1993). Halfway round the harbour: an autobiography (1. publ ed.). Auckland: Penguin Books. ISBN0140179852.
