The paragraph reveals its historical context through references to "the Arctic darkness," the discovery of "a yellow metal," and the booming "steamship and transportation companies." These details suggest a time during the Alaska gold rush, when thousands of men flocked to the North in search of gold. The mention of "heavy dogs, with strong muscles" and "furry coats" highlights the harsh, cold environment of the Northland, where durable dogs were essential for survival and transport.
Based on what you know about the Alaska gold rush, miners wanted dogs primarily for transportation over snow and ice. Dogs, specifically sled dogs, were crucial for hauling supplies and facilitating travel in the challenging Arctic conditions.