Apple Inc workers in Maryland voted on Saturday to join a union, becoming the first retail employees of the tech giant to unionise in the United States.
More than 100 workers in Towson near Baltimore "have overwhelmingly voted to join the International Association of Machinists and Aerospace Workers," the union said on its website.
The local workers, forming the Coalition of Organised Retail Employees, "have the support of a solid majority of our coworkers," they wrote in a letter to Apple chief executive Tim Cook.
"This is something we do not to go against or create conflict with our management," they wrote.
An Apple spokesperson, responding to Reuters request for comment, said by email the company had "nothing to add at this time."
Unionisation efforts are gaining momentum at some large US corporations, including Amazon.com Inc and Starbucks Corp.
Apple workers in Atlanta who were seeking to unionise withdrew their request last month, claiming intimidation.
Some current and former Apple workers last year began criticising the company's working conditions online, using the hashtag #AppleToo.