More than a dozen employees began their protest at 3 p.m. outside the AT&T wireless store at 1501 Walnut St.in Center City. "We're really the heart of the company", said Mark Davis, an AT&T Mobility worker in Washington, D.C.
The weekend strike is being held across 36 states and the District of Columbia and involves an estimated 40,000 union members.
The CWA threatened the move could disrupt "a large number of retail stores" across the United States over the weekend.
Landline workers in California and Nevada picketed for a day in March to protest work rules for some in-home technicians and moves to replace US call-center jobs with contractors hired overseas.
Employees claim the company is demanding more work for less and it is looking to third party dealers and overseas workers.
The groups on strike represent four different union contracts, the CWA said.
The CWA was involved in a 45-day strike past year by 40,000 Verizon wireline workers that ended in June. "This is a warning to AT&T: there's only one way out of this now-a fair contract-and we'll settle for nothing less". Others are employed in call centers spread out across the country.
"This may be the largest retail strike in US history".
AT&T has been under pressure to control costs as its biggest business - wireless phone service - has matured and faced rising competition from Verizon, Sprint and T-Mobile.
Just over half of the employees work for the company's wireless business, primarily in call centers and retail stores, and have been without a long-term contract since February.
The closings have devastated cities and towns across the USA where unionized call center jobs represent some of the best employment available in working-class communities-like in Ridgeland, Mississippi, where AT&T shut down a call center employing 110 people.
The strike is expected to end Sunday evening, with workers returning to the job Monday.