NEW YORK (AP) — U.S. ports from Maine to Texas shut down Tuesday when the union representing about 45,000 dockworkers went on strike for the first time since 1977.

A lengthy shutdown could raise prices on goods around the country and potentially cause shortages and price increases at big and small retailers alike as the holiday shopping season — along with a tight presidential election — approaches. “First and foremost, we can expect delays to market. And those delays depend on really what the commodities are and priorities at the ports and how quickly things move,” said Mark Baxa, president of the Council of Supply Chain Management Professionals.

The International Longshoremen’s Association is demanding significantly higher wages and a total ban on the automation of cranes, gates and container-moving trucks that are used in the loading or unloading of freight at 36 U.S. ports.

Those ports handle roughly half of the nations’ cargo from ships. The contract between the ILA and the United States Maritime Alliance, which represents the ports, expired Tuesday. Some progress was reported in talks late Monday, but the union went on strike anyway.

The union’s opening offer was for a 77% pay raise over the six-year life of the contract , with President Harold Daggett saying it’s necessary to make up for inflation and years of small raises. ILA members make a base salary of about $81,000 per year, but some can pull in over $200,000 annually with large amounts of overt.