Moved to heraldry and tartans section.

Quote Originally Posted by Mattg
"Gaelic is at the heart of all the Irish surnames that can be found throughout the world today. The original Gaelic form of the name MacGlashen is Mac Glasain or Mac Glaisin; both are derived from the word glas, which means green or gray-green.

Spelling variations include: MacGlashan, MacGlashen, MacGlasheen, MacGlassan, MacGlasson, Houneen, O'Houneen and many more.

First found in county Clare where they held a family seat from ancient times. Some of the first settlers of this name or some of its variants were: Robert MacGlashan with his wife and two children who arrived in New York in 1775 and moved on to Georgia, as well as John MacGlashan, who was recorded in Savannah, Georgia in 1855."
www.houseofnames.com
Not sure if that's you, but that's what I found...
House of Names is a "bucket shop" that sells "family crests" and very generalised surname histories. Not reliable.

Usually geographic residence determined which clan someone might affiliate with; if you can track your ancestors down to the traditional lands of a particular clan, then that is one way to determine affiliation.

You might send a message to our own Matt Newsome, the curator of the Scottish Tartans Museum in Franklin, North Carolina. Matt might have some resources at his disposal with the information you seek.

Matt's web sites:

www.albanach.org
www.scottishtartans.org

Regards,

Todd