In recent days, Starbucks workers held their biggest-ever strike, union says.

Work stoppages on Tuesday mark the last wave of an escalating strike.

Workers have escalated the strike each day since it began on Friday.

Starbucks union's strike will expand through Christmas Eve to a dozen metro areas, while the Teamsters union says workers for Amazon at a California airport have joined other workers protesting.

Striking baristas brought business to a halt in almost 50 stores nationwide on Sunday across multiple cities, Workers United said. ABC News' Alexis Christoforous reports.

The Workers United union strike is in its third of five planned days amid a busy holiday season for Starbucks.

Thousands of Starbucks baristas and delivery drivers for Amazon are protesting the respective retail giants nationwide during the busiest shopping season of the year, according to their unions.

Thousands of Starbucks workers, as well as delivery drivers for Amazon, are picketing just days before Christmas.

ABC News' Zohreen Shah reports from Burbank, California, on the escalating strikes that will continue until Dec. 24.

Why are Amazon and Starbucks workers striking over the holidays? “This is a time when both companies make a lot of money,” one expert said.

Eleven thousand unionized baristas at over 530 Starbucks locations are going on strike at company-owned stores in Los Angeles, Chicago and Seattle after negotiations broke down.

The workers union representing Starbucks baristas across the country announced members in Los Angeles, Chicago and Seattle will go on strike beginning Friday.

CEO of Starbucks Brian Niccol talked about forthcoming changes and progress happening at the popular coffee chain.

Brian Niccol speaks to “GMA” about how he plans to reinvigorate Starbucks, including a plan to get drinks to customers faster.

Starbucks announced Nov. 14 is Red Cup Day when customers can receive a free reusable cup with a holiday drink purchase.

Here's what's new at Starbucks this holiday season starting Nov. 7: Cran-Merry Orange Refreshers, Salted Pecan Crunch Cold Brew, Turkey Sage Danish and more.

Starbucks announced it will no longer charge extra fees for customizing beverages with nondairy milk options at U.S. and Canada stores.

The coffee chain will drop the extra charge for customers who purchase their beverages with nondairy milks, such as soy, oat, almond and coconut.

Starbucks CEO plans to simplify the menu, return to community coffeehouses, and create better opportunities for baristas.

Why the new Starbucks CEO will scale back on promotions to help reduce strain on staff and elevate the brand's premium presence.

The company’s new CEO is cutting back on promotional offers in hopes of repositioning Starbucks back to a premium brand while also reducing strain on employees.

The new CEO of Starbucks Brian Niccols penned a letter to customers and employees about his plans for the future of the coffee brand.

Starbucks is one of many businesses impacted by the global IT issues from CrowdStrike outage and the coffee chain alerted customers the app orders are still down.

Good news for travelers as Starbucks announced a new external rewards partnership with Marriott Bonvoy to earn more points.

With its “pairings menu,” Starbucks is offering a combination of hot or iced coffee or tea with a croissant for $5 or a hot breakfast sandwich for $6.

All the new Starbucks summer menu items from Berry Refreshers to Pineapple Cloud Cake, plus in-app discounts for the loyalty rewards members.

Starbucks' shares have plummeted about 17% in value since last week as sales slump.

ABC News business reporter Alexis Christoforous breaks down national business headlines.

Starbucks unveiled three new spicy drinks along with a new spicy foam to add a fiery test to spring.

Starbucks has created Oleato, a new lineup of coffee drinks infused with premium Sicilian olive oil.

Starbucks will become the first nationwide coffee retailer to accept reusable cups for both drive-thru and mobile orders.

Customers will save 10 cents when using a reusable cup and will earn more stars in the company's rewards program.

Thousands of Starbucks employees at hundreds of stores are walking off the job, the union says.

Thousands of Starbucks employees nationwide are set to walk off the job on Thursday, coinciding with Red Cup Day, one of the company’s biggest days of the year.

Thousands of employees at hundreds of stores will walk off the job, union says.

Thousands of unionized workers from hundreds of locations across the country are planning to walk off the job on Thursday in what they are calling the “Red Cup Rebellion.”

The announcement arrives amid a union campaign at Starbucks stores nationwide.

Starbucks said it will also reduce the minimum number of days an employee must work in order to qualify for paid vacation benefits.

Over 150 companies have released statements condemning the initial Hamas attack.

Over 150 companies have released statements condemning the initial Hamas attack.

In celebration of Hispanic Heritage Month, ABC News' Melissa Adan speaks with Philadelphia artist Manuela Guillen whose colorful designs are featured at Starbucks across the country.

KaleJunkie creator Nicole Keshishian Modic shows her recipe that's a dupe for Starbucks' popular apple crisp fall drinks.

A contact-free method of checkout that uses geolocation to identify the customer in the drive-thru lane.

A New Jersey federal judge has ordered Starbucks to pay a former employee who was awarded $25.6 million in a wrongful termination suit an extra $2.7 million in damages.

Striking Starbucks workers claim that some cafes are not allowing workers to put up Pride decorations.

More than 3,000 Starbucks workers said they are set to strike over company policies regarding pride celebrations, calling the walkout “strike with pride."

Shannon Phillips received $25.6 million in damages after a six-day trial.

A New Jersey jury unanimously sided with Shannon Phillips, claiming “her race was a determinative factor” in Starbucks’ decision to fire her in 2018.

Former CEO Howard Schultz was grilled before a Senate committee Monday over allegations the corporation led an "illegal union-busting campaign" against its workers — a claim Schultz denies.

The former CEO of Starbucks defended allegations of union busting during a Senate hearing.