Walker / M'Nuccator
In the Gaedhealtachd (the Gaelic-speaking highlands) Walker was the English equivalent of Mac-an-fhucadair, "Son of the fuller"; fulling being the cleansing and thickening of newly woven cloth - a process that was sometimes known as "waulking" (which really means "working" the cloth, but because this can be done with the feet it is sometimes thought of as walking!). Since every pre-industrial community had weavers the majority of Walkers are unlikely to be M'millans; but an ancient connection between the two names is clearly evident - particularly in Argyll, though not only there.
The place-name Ballanucator (Bal-an-Fhucator - i.e. Walkerstown) appears in Mentieth on the lands of the old lairds of Leny (see sept of Leny), who were descendants of Maoldonich mac Malcolm mhic Mhaolain; and the earliest Walker on record in the company of a M'millan is D. Joh. Walkare rectore de Luse who appears as a witness to a Galloway charter in 1511 along with Moricio Makmillane.
One of the earliest records of the Gaelic name occurs - perhaps significantly in view of the M'millan connection - in Knapdale in 1547, when Donald roye McInocader appears as a witness; and in 1643 a Martino M'Nowcattar is documented in Inverary. It's impossible to say if either of these early Mac-an-fhucadairs were M'millans; but the record, also in 1643, of Donald Fuccader... alias McEwin V'Gillemoyll (i.e. MhicGhillemhaoil) on the island of Seil in Lorn shows that the sept was in existence by the first half of the 17th century.
Other members of the sept appearing in 17th century records include Ivar M'Nowcatter in Corro in 1673 [JRAI (Justiciary Records of Argyll & the Isles)]; Donald McNowcater in Cars - with John McMillan - in 1675 [JRAI]; Martein Walker and his daughter Margaret in Inverary in 1675 [JRAI]; John McNowcater and his spouse Margaret NcDougall in Fisherland - with William Brown - in 1675, and in 1680 with Donald Walker in Fisherland [JRAI]; Donald Walker in Inverary in 1699 (probably the same man that was in Fisherland in 1680) [JRAI].
Other recorded versions of Mac-an-fhucadair include MacInhuggater and Mackinquorcher.
This sept-name is well-known in Scotland today because of the great success of Walkers Shortbread Ltd. of Aberlour on Spey in Banffshire. This family firm was founded in 1898 by Joseph Walker, was carried on by his sons James and Joseph II, and is now headed by his grandchildren Joseph III, James II, and Marjory Walker - who has been a generous supporter over the years of the Clan MacMillan Society (of Scotland).