evidence: Walmart already has a huge U.S. footprint. But the retail giant sees room to get even bigger. [...] The big-box retailer is the largest private employer in the U.S. with about 1.6 million employees. About 90% of the U.S. population already lives with 10 miles of a Walmart store. With the expansion, Walmart is signaling that it sees its brick-and-mortar locations as a key part of the future, despite heightened competition with online players like Amazon and Shein, and its own push for growth of online sales and its third-party marketplace. [...] New stores will also have more sustainability features, such as energy-efficient lighting, he said.