I´ve done some surfing today...
I found a page (http://familytreemaker.genealogy.com/users/h/o/c/Robert-S-Hockman/GENE6-0001....
about an American Hagman(n)/Hackman/Hockman family that traces its roots back to Switzerland. It is suggested that the name refers to Haag, a small village near Salez in St. Gallen, from where numerous Hagmans supposedly carried the name with them to Zürich and Thurgau in the 14th and 15th centuries. In the 17th century, Mennonite Hagman families were living in Rheinland-Pfalz.
This is interesting since the Swedish king Charles X was the son of a Margrave of Pfalz-Zweibrücken. Is it possible or likely that he brought with him or invited some Hagmans from the old country when he became king?
/haggmanwebmaster