The documentation of Assyrian law is given in the answer to this question. What is the earliest history of Middle Eastern women wearing veils for modesty while in public?
What historic documents do we have to support the following historic statements?
In wearing a veil, we Sisters insert ourselves into a very long tradition, a tradition which pre-dates Christianity. In ancient Greek culture, respectable married women wore a veil. Extant is an Assyrian law from ca. 1400–1100 B.C., which states that married women and widows are never to be in public without a veil. In ancient Greece, it was not considered seemly for a married woman to reveal her hair to the eyes of men other than her husband. In Rome, a veil called flammeum was the most prominent feature of the costume worn by the bride on the day of her wedding.
Throughout the greater part of history, married women wore head coverings. Even Protestant women typically wore head coverings during church services (a scarf, cap, veil, or hat). We might think today of the Mennonites or Amish who still follow such a tradition. Until the 20th century, everyday people would have readily understood the symbolism of the veil. Even today, we retain some remnants of the tradition of veiling in secular culture, at least in the form of the wedding veil.