Final answer:
Abraham Darby was an innovator in improving the smelting process of iron ore by introducing the use of coke which lowered the cost of iron production and increased availability.
Step-by-step explanation:
The significance of Abraham Darby in history is that he was an innovator in improving the smelting process of iron ore. He introduced the use of coke, a form of carbon formed by heating coal, as the reducing agent in the smelting process. This replaced the traditional use of charcoal and significantly lowered the cost of iron production while increasing availability.