I have been researching the name Ferrier/Farrier/Ferrar variations for the last 30 years and have a large database of about 226,000 ferriers. I am more than willing to share information and see what we can fit together.
My own branch of Ferrier started out life as Ferrar in Aberdeen in Scotland about 1700.
As far as I can figure it the majority (about 80%) of the Ferriers come
from an area of Scotland called Angus. They got the name Ferrier because they
ferried people across rivers. There were definately parts of that source
which moved locally to Edinburgh and Aberdeen. Another source was Normandy
in France where early on a de-Ferriere/de-Ferrar came over to England with William
the conqueror. This family later changed their name to deFerrer and there
are several towns in england with the part of their name being De Ferrer.
There is a branch of that Family it is believed, (although never definitively traced) in the Norfolk area of England. There are also significant pockets of the name which came from France, Ireland, Portugal, and Italy. Naturally there are many corruptions of the name and one which is poularly quoted is a corruption of Farrier
a person who shoes horses. Several Ferriers emigrated to the US, Canada, and Australia. There are many in Australia mainly from Scottish descent. There are several in Ontario who come also from Scotland. There was a large family in the Orange county area of NY which came from an Irish Ferrier.
There is also a large family around Mifflin County Pennysylvania who, came from Scotland. I know that some of the Ontario Ferriers came via the US and also went back to the US and I believe that some of those were, from Missouri but have never found anyone, who had much information about them.
I have a lot of fragmented information on US Ferriers from Census records, death records telephone records. Where I can trace someone back to england/wales or scotland I have a lot of information on birth/death/marriage census information.
My own antecedents come from Aberdeen in Scotland, then to London via the north of england, following the docks. They have been in London area since about 1850. I am trying to trace other parts of the Ferrier family to
eliminate irrelevant branches of the family.