There are quite a number of Kadars even here in the US. As far as my family is concerned I am the only one living in the US. My brother lives in Hungary and last year he had managed to take a picture of our family tree that was stored at a relative in Transylvania (now Romania). From that our oldest known and verified ancestor was living in Ernei (in hungarian Nagyernye) Transylvania, north-east of Tirgu Mures (Marosvasarhely) from the start of the 1800-s. He was a teacher in a school for more than 50 years. His first name was Janos (John). I do not know how much you know of your ancestry lineage, I would be interested to find out. There is a social WEBsite in Hungary, www.iwiw.hu
that actually has a club of Kadars in it.