U.S. ports from Maine to Texas shut down this week when the union representing about 45,000 dockworkers went on strike for the first time since 1977.

Some 45,000 dock workers went on strike Tuesday, idling ports from Florida to Texas, but the walkout’s impact on consumers and the larger economy hinges on how long it lasts. A port strike lasting more than a week would likely drive up the cost of fruit and vegetables at the supermarket,