The company opened two modest facilities outside Allentown, Bethlehem’s neighbor to the west, a place made famous by a Billy Joel song about the death of factory jobs. Other retailers rushed in, drawn partly by incentives, including abatements and credits, allowing companies that developed on the steel mill land to save hundreds of thousands on their tax bills over 10 years.

As a result, the stretch of eastern and central Pennsylvania that includes the Lehigh Valley has grown faster than any other market in the country over the last five years, according to CBRE. While retailers tend to bulk up their facilities with temporary helpers around the holidays — Amazon has announced plans to hire 120,000 seasonal employees by the end of the year — they have also taken on an army of full-time workers. Warehouse employment in a two-county area that includes Bethlehem jumped to 15,200 in 2017, from 5,200 in 2010.

“I don’t know of another place in the world that has gone from a submarket to a global hub in eight years,” said David Egan, the global head of industrial and logistics research at CBRE. “It’s undeniable that it is a key, crucial market for global trade.”

Some of the biggest players in the warehouse game have staked a claim to Lehigh Valley land. Walmart has two huge facilities in Bethlehem. FedEx is building one of its biggest ground locations in the nation in the area, and the United Parcel Service opened a new hub near the New Jersey border last year to handle the torrential volume of traffic coming through eastern Pennsylvania.