According to Hanks & Hodges' A Dictionary of Surnames (Oxford U. Press) Harding is an English surname, from the Old English personal name Hearding.

Mind you, I don't have a copy of Black's Surnames of Scotland at work to cross-reference it. Hmm...off to order a copy for the reference section.

I used to know a fellow park ranger who worked at the St. Louis Arch whose surname was Harding...I wonder if I still have Doug's e-mail addy?

Regards,

Todd