Middle Names or Not

Did our ancestors have middle names? I was getting conflicting answers to that question so I googled it. This is what I found:
The Amish don't use middle names, but with the increase in government paperwork, they now use middle initials. Usually the first initial of the father's name is given as a middle initial for their children's names. This is done out of respect for the father. The Mennonites, on the other hand, use the first letter of the mother's maiden name.
In our family:
Henry H. and Sarah (Jantzen) Thesman's children were Franz J. Thesman and Anna J Thesman, etc.
But in the Abraham and Katharina (Regier) Schmidt family, the children were Jacob A. Schmidt and Elizabeth A. Schmidt. 
Maybe it was where they lived that made a difference in their choice. Does anyone know?
What we do know and that I find interesting is the way the kids added to their Middle initial. Anna Thesman chose "Julia" for her middle initial "J".
In the Schmidt family, Henry picked "Andre" for his middle initial of "A".

I see a lot of middle names for the children born around 1920 and later. Maybe a middle name is not listed on the birth certificate, but by the time they learned to write their name they knew their middle name.


Here is Jacob A. Schmidt and Anna J. Thesman's marriage license signed by Rev. Voth.