Amazon announced on Thursday that Boston is among the 20 finalists for its second headquarters. 

Other cities on the list include New York, Newark, Pittsburgh, Philadelphia, Raleigh, Atlanta, Miami, Los Angeles, Dallas, Austin, Denver, Chicago, Columbus and Indianapolis. (One city in Canada — Toronto — also made the list.)

Boston's bid, a 218-page document, would utilize the Suffolk Downs site, the 160-acre horse track in East Boston and Revere. The site is considered desirable by many city officials because it's close to the airport and is served by the MBTA's Blue Line. It's also among the largest shovel-ready development sites in the city.

"I am proud that Boston is on Amazon's shortlist for its second North American headquarters," Boston Mayor Marty Walsh said in a statement. "As a thriving city with a talented and diverse workforce, culture of innovation and opportunity for all, I see no better city than Boston for Amazon to call their second home."

At a press conference later in the day, Walsh said the city is waiting to hear from Amazon to see what the next steps are and that Boston officials aren't prepared to talk about tax breaks or other incentives yet.

"We're not even near that," Walsh said. "I don't know what the incentives will be. I don't know if they're looking for incentives. We're going to work through all this stuff as we move forward."

Gov. Charlie Baker echoed similar sentiments at a separate press conference. He said the state is waiting for more details and instructions from the company. "The next move is going to be up to them," the governor said. "And we look forward to wherever that conversation takes us."

With the decline of horse racing, there has been speculation about what would happen with the Suffolk Downs property. Former Boston Mayor Tom Menino supported a bid by the owners of Suffolk Downs to open a casino, but that license was awarded to Steve Wynn's Everett proposal. 

House Speaker Robert DeLeo, whose father worked at Suffolk Downs, has long supported the racing industry and its employees. He has also been in favor of redeveloping the site as Amazon's new headquarters.

"With a highly educated, technology-friendly workforce, Boston is the perfect place for Amazon to put down roots," DeLeo said. "The legislature has focused on providing a stable and predictable environment for business, and we have backed programs like the Intern Partnership, MassCAN and STEM Starter Academy to prepare the innovators of tomorrow. I was honored to collaborate with the mayor on our bid and look forward to working with Gov. Baker, Mayor Walsh and my colleagues in the legislature as we strive towards bringing the company here." 

Amazon has said it will invest more than $5 billion in construction to create its second headquarters, which is expected to employ roughly 50,000 people. The Seattle-based company received more than 200 proposals from cities around the country. A number of cities in New England, including Somerville, Worcester and Providence, submitted bids. Amazon's short list only identifies metro areas, not specific development sites, and Somerville Mayor Joseph Curtatone says he hopes his city is still in the running in some capacity.

"I'm optimistic that there will be some regional flavor or regional component to anything Amazon wants to do," Curtatone said. "And again, it remains to be seen. This is the shortlist, though maybe the first of more than one shortlist."

Somerville's bid proposes a string of parcels connected by the MBTA, including Assembly Row and Union Square in contrast to Boston's rival bid, which focused solely on Suffolk Downs. A statement from the Baker administration says it will continue to include Somerville in it's efforts to woo Amazon.

The potential deal, however, does have its critics, who argue that luring companies with major tax breaks isn't always in the best interest of the city or state. They maintain that many of the things — like an educated workforce and an established transportation system — that make Boston and its surrounding suburbs an attractive place to grow a business require public investment.

And, there are issues outside of the terms of the agreement Boston might make to lure Amazon. Escalating housing prices in the area have already put home ownership out of reach for many. The addition of 50,000 high-paying jobs could strain an already competitive market.

"The questions are, if Amazon comes with thousands of white collar jobs, how is that going to impact the housing situation in Massachusetts?" asked State Sen. James Eldridge. "How is that going to impact transportation?

Amazon already employs about 1,000 people in Boston and Cambridge. It has also signaled a desire to lease up to one million square feet of office space in Boston's Seaport district independent of its move to open a second headquarters. 

This story has been updated to include new information.

Reporters Marilyn Schairer and Craig LeMoult contributed to this article.