Following the revolution in 1809 he became a member Government and in the following year received a promotion to Rear Admiral. He was also was made chairman of the Göta kanal directorate charged with constructing a canal across Sweden. The canal would only be completed in 1832, after von Platen's death, but during its construction, he did discover two skilled mechanical engineering brothers John Ericsson and Nils Ericson.
He was created Viceroy of Norway on November 26, 1827, a position which he held until his death in Christiania, the Norwegian capital, on December 6, 1829 . He was married to Hedvig Elisabeth Ekman.
von Platen's grave is at the side of the Göta Kanal in Motala, where it is something of a tourist attraction, especially for canal visitors.
See also: History of Sweden