Tar production became a major industry because ships, farms, buildings, roads, ropes, roofs, and industrial processes needed large quantities of dark preserving and binding materials.
Tar production grew wherever demand was large enough and raw material was available. In forest regions, wood tar could be made from resinous pine and other timber resources. In industrial regions, coal tar appeared as a by-product of coal processing. These streams fed very different markets, but both show why tar mattered economically.
The maritime world was one of the great drivers. Wooden ships and natural fibre ropes needed constant maintenance, and navies required reliable supplies. The naval stores trade included tar, pitch, rosin, turpentine, and related products. A fleet was not only built from wood and iron. It was maintained by barrels of sticky materials.
Farms and buildings also used tar because weather damages everything outdoors. Fences, gates, posts, roofs, sheds, carts, tools, and livestock structures all needed protection. Later industrial chemistry found further uses for coal tar and its fractions.
The industry was therefore not based on novelty. It was based on maintenance at scale. When a society owns millions of wooden, fibrous, and exposed surfaces, a material that slows decay becomes important enough to organise, trade, tax, and regulate.