Career
In the beginning of his career he worked in the Swedish Foreign Office and had served as Swedish-Norwegian legation-secretary in Copenhagen during the Crimean War. In the late 1850s he served as envoyée to Italy. In 1861 he was appointed minister to the United States and served to 1864, when he was replaced by Baron de Wetterstedt.
Piper was very close to Secretary of State William H. Seward.