Historians accepted 1757 as his birth year until about 1930, when additional documentation of his early life in the Caribbean was published, initially in Danish.
Ajaloolased aktsepteerisid 1757. aastat tema sünnipäevana kuni umbes 1930. aastani, kui avaldati dokumente tema varasemast elust Kariibi mere piirkonnas, esialgu taani keeles.