Some actual history: I picked the 1700s for the meme because the modern standard version of the Humpty Dumpty nursery rhyme is based on the one that was created in the late 1700s with only some slight changes. In that version, it says “ Four-score Men and Four-score more, Could not make Humpty Dumpty where he was before.” instead of “ All the king's horses and all the king's men couldn't put Humpty together again.” It’s a different word choice, but has basically the same meaning.
Allegedly Humpty Dumpty can be traced back to at least the late 15th century and the most popular suggestion for the inspiration behind it is that Humpty Dumpty might be King Richard the 3rd. Richard was a hunchback (aka had a hump… Humpty could be a reference to this hump) and his horse was called Wall (Humpty Dumpty sat on a wall before he had a great fall). So the beginning of the nursery story could maybe be about King Richard The 3rd on his horse. Richard started being king in 1483 and was king until he was overthrown in 1485 by Henery Tudor who defeated the king in combat at the Battle of Bosworth Field. During the battle, the king allegedly fell off his horse Wall which would also account for the story behind Humpty Dumpty falling off of a wall.