So here goes my proper go.

A disclaimer first. I'm a student studying Geomatics (surveying) not a proper historian. So I doubt I'll be as eloquent as many of the posters on this sub, and my answer will be fairly disjointed. My reference is from "Brown's Boundary Control and Legal Principles" 7th edition.

A piece of background information before diving in. In our modern time we usually use what is called a "Metes and Bounds" description to identify boundaries. This is a combination of "Metes" or measurements such as distance and bearing, and "Bounds" or boundaries which describes other lines such as an already established boundary line from a nearby area.

In effect, humans have always created boundaries. This is simply essential once you have two groups occupying the same, or nearby, areas, and we can see it in many places.

In Europe, and subsequently America, many places have documented examples of how borders were marked. While it was not until we had the ability to use writing and mapping that we began to develop a formal system, We have "monuments" such as "Boundary Stones" marked with a cross symbol from the medieval period of England which were set at the corners which defined the boundaries, and the Old English term "Meare"(Boundary) seen in the names of certain rivers and streams ("Merebrook, Merebeck") is seen as indication that they were used as defined boundaries.

A practice that has also existed and is documented up to recent time since at least the 1600's, but is known to be far older, is "beating round the bounds". This is a practice where the town would gather, and walk round the boundaries of their town to cement them in their memories. In this practice they would often select young children, and give them a "unforgettable" experience at each corner monument. "In 1687 William Gregory, testified that, as a child of 7 in 1601... As the group passed one of the boundary stones one of the older gentlemen called to the boy, "William, put your finger on the meerstone..." William related "that in doing so he layd hold of my hand and did wring one of my fingers sorely so that for the present it did grieve me very much"". We will note the term "Meerestone" from the same term "meare", and this is taken as an example of how they would make sure the younger members of the town would be able to recall the markers of the boundaries.

To reach back farther, it is noted that the Ancient Greeks worshiped the goddess "Terminus" as the protector of boundaries. And the Romans also paid great homage to this god.

Now then, while I can detail more, the best example of what you are looking for will most likely be "Kudurru" or boundary stones from the Ancient city of Babylon. For this I am focusing on a stone which is dated to more than 3000 years old. This stone is an ancient Babylonian Boundary marker, looking at the text historians found that it described in effect a land deed, even marked with the name of the surveyor who marked the area. You may look up more on this but the most important part for your question will be the text on it. The wording is pretty thick so I am editing to save space.

The piece of most interest will be this.

"Twenty gur of grain-land, in the district of Al-Nirea, on the bank of the Zirzirri Canal, in Bit-Ada... Marduk-Nadin-Akhe, King of Babylon (looked with favor on his servant Adad-zerikisha)... and according to the word of the king of Babylon twenty gur of grain land, a gan, measured by the great cubit, being reckoned at thirty ka of seed, for (his servant)... On the upper length, to the north, the Zirzirri Canal, adjoining Bit-Ada and the field of the Governors's house; on the lower length, to the south, the Atab-dur-Oshtar Canal, to the East, adjoining Amel-Eulmash; the lower width, to the West, adjoining Bit-Ada. According to the word of Marduk-Nadin-Akhe, king of Babylon, was the deed sealed. Enlil-zer-kinim the son of Arad-Ishtar, was the surveyor of the land"... The remainder of the passage is further text asserting the ownership of the land and calling upon the blessings and protection of the various gods against any who would try to falsely contest the recipients claim to ownership.

The above passage, is a "Metes and Bounds" description. The Babylonians would make two records, one would be written down in a temple as an official record, the other would be scribed onto a clay tablet which would then be used as a boundary marker on the land in question.

So in summation to your question. Yes, the concept of borders has existed for most of our written history and is noted and discussed by societies and civilization many thousands of years old.

I hope this provides some of the answers you were looking for.