So, we have William Everett Mitchell as one parent and Maggie Patterson as the other. I guess that the only option I have right now is to assume that Maggie Patterson was indeed his mother, though I strongly suspect that she could have been a stepmother, or a foster-mother, someone that helped to raise him after the orphanage.
So lets just touch on some Irish issues. As we do not know where in Ireland Maggie was from, I will deal with a few general Irish themes.
There is a strong belief that there was a connection between Scotland and Ireland. This is true on many levels. There was trade and movement almost constantly between the two. Mythology too, has themes that hint at cultural connections. Reference the Giant's Causeway for a good yarn.
Names like Mitchell(He who is like God) could have started out as Michael, Mitchie, or other variants on the name. Mac Michie was suggested in one of the generic genealogy sites that print out the coats of arms that are commonly available on line. Possibly Mc Michie would strengthen the perception of the Irish name being stronger. Mac Michie was one of the names in Scotland that are generally thought to be a cadet branch of Mac Donnell, one of the great clans.
Patterson...in Ireland is probably from son of Patrick. Here is a published account...Scottish and northern English: patronymic from a pet form of Pate, a short form of Patrick. Irish: in Ulster of English or Scottish origin; in County Galway, a surname taken by bearers of Gaelic Ó Caisín ‘descendant of the little curly-headed one’ (from Gaelic casán), which is usually Anglicized as Cussane. Does that sound a little far fetched to you...well, I am no expert in language descent.
A piece of "Celtic" silver from my collections. I feel blessed to have this, look at the decoration!
There are no genetic connections between the people of the British Isles and the Celts. (I know this will be an extraordinary statement for many who think of themselves as Celtic in heritage) The Celts were from the area around Austria, southern Germany and reaching into central eastern France. While the Art and language of the Celts spread all over the place, the Celts themselves are pretty much confined to those areas. There was a spread of the art and language through trade, and many cultures were heavily influenced by this. The Atlantic coast, including early Spain and Portugal(pre Arab), Brittany, Cornwall, Wales, Ireland and Scotland were trading partners in a vast network that included Celtic speaking Greeks who traded by way of Marseilles, France, Romans and other merchants who were in search of hides, tin and Slaves among other things. (The Early Greeks called the Celts: Celtoi) The Art was extraordinary, and so was picked up by local cultures. The Language was a sort of Lingua Franca for trading, so it became necessary to conduct trade with a number of cultures, long before Latin appeared. As a result, I hope it heals the sting a bit when I say that the peoples of western Britain, owe the Celts for some wonderful things, but they were a separate and marvelous people long before the Celts were heard of.
The Irish-Scottish connection is very old, not just in the 19th century that many think of. There was a kingdom within a century or two of Rome's collapse in the 6th and 7th centuries at its height.
This was a kingdom that was made up of the modern Ulster, or a portion of it, and the modern Argyle and Lochan areas of Scotland.
The kingdom was named Dalriada, and there are a number of spelling variants. Basically this is something like Riada's portion. The Irish kingdom developed over time, expanding into the finger-like peninsulas of western Scotland. The original Irish people who entered Pict lands were the Gaels, also known as the Scoti. Argyle translates into the "Coast of the Gaels" In any event they were a single kingdom spread between the two present day countries. The island of Iona lies almost dead center between the two halves and that is where St. Columba set up his very influential monastic settlement.
St. Columba arrived in The capital, named Dunadd, and from there, he and his followers infiltrated the Pictish lands of Scotland, bringing Christianity and replacing the old Pictish language with the Gaelic that they brought with them from Ireland. Of course there was a slightly different spin on the Gaelic as differing populations will always do. Now I would have bet that the civilizing of the area went the other way, but Ireland to Scotland seems correct, at least in terms of Christianity and language. We must remember that Ireland was never conquered by Rome, so the culture and the Christianity developed independently and stuck after the Romans left. It took the Normans, Tudors and the Stuarts to bring Ireland into the British sphere instead of the other way around.
The Columba "invasion" occurred at the end of the 500s, so by the end of the 600s and the early 700s, Venerable Bede wrote in his "History of the English People", that five languages were spoken in Britain. Anglorum, or English,.... British(Bretton) which is Welsh,... Scottish, which is Irish(Thanks Columba),... Pictish, which was dying out a bit by this time,... and Latin which was still in use everywhere that the Roman's were strong, (including a large part of Scotland strangely enough), and anywhere that the Latin church was strong. Bede wrote in Latin of course.