This superstition originates 5,000 years ago in ancient Egypt. A ladder leaning against a wall forms a triangle, and Egyptians regarded this shape as sacred (as exhibited, for example, by their pyramids). To them, triangles represented the trinity of the gods, and to pass through a triangle was to desecrate them.
This belief wended its way up through the ages. Centuries later, followers of Jesus Christ usurped the superstition, interpreting it in light of Christ's death. Because a ladder had rested against the crucifix, it became a symbol of wickedness, betrayal, and death. Walking under a ladder courted misfortune.
In England during the 1600s, criminals were forced to walk under a ladder on their way to the gallows.
I will keep you posted with the rest coming up gradually..