Edmund and others, this is NOT my family, but a quick search reveals that the surname appears all over the world, literally. FHL transcriptions at familysearch.org lists a number of Dohnerts from all over--and these are only the ones they happen to have transcribed. They include:

Salome Dorothea Donhert, bapt 27 Aug 1773, Saint Peter's, Denmark; daughter of Johan Gottfriend Dohnert and Elisabeth Petersen.

Johann Bathasar Dohnert born 3 Oct 1775 to Johann Gottfried Dohnert and Elisabet Petersen, also Denmark

Mariana Catharina Dohnert b 1 Feb 1778 to Johann Gottfriend Dohnert and Elisabet

Salome married Christian Peter Kirchheiner and had Marie Caroline Louise Christensen bapt 12 May 1803 Praesto, Denmark

Antonia Esperansa Luisa Dohnert b and bapt 26 Aug 1816 Santos Justo y Pastor, Barcelona, Spain, daughter of Joan Dohnert and Fracisca Fuchs

Frederich Otta Dohnert b 14 Sept 1891, Monifieth, Forfar, Scotland, to Henry Emil Dohnert and Agnes Gilmore Douglas Dohnert

Fritz Dohnert, b in 1847, Cuba (died in Brooklyn, NY 1903)

Edgar and Anna Dohnert arriving at Ellis Island 1913 from Belostok, Russia

Bruno Dohnert, age 24, arriving at Ellis Island 1911 from Dresden, Germany

There are more--including 13 in the 1860 US census--but you can do your own microfilm search. I hope this provides some good leads.

Laura in NC