Historical cost is the original cost paid for an asset.
Let’s say a company buys a truck for $30,000. Over the course of the years they may take depreciation deductions totally $25,000. On the company books the truck would be listed at a value of $5000 ($30,000-25,000). But if someone asks what the company paid for the truck, they are asking for the historical cost of $30,000, the original purchase price.