Uber plans to hire 2,000 employees in Chicago to help fill the 463,000 square feet it leased in the city’s refurbished Old Post Office building, the company announced Monday.

The space, the size of 24 football fields, is expected to help grow Uber Freight, which enables carriers, especially owner-operators and small fleets, to find and book loads through a mobile app.

Uber (UBER) signed a 10-year lease for the space last month. It will serve as Freight’s first engineering hub outside San Francisco.

“Chicago is going to be one of the important cities for Uber,” CEO Dara Khosrowshahi said during an “L” ride through the Loop to the Post Office. “This is a big bet that we’re making.”

More than 1,000 of Uber’s more than 9,000-member domestic workforce already operates out of two offices in Chicago, making the operation second in size only to the company’s San Francisco headquarters. The two offices, which comprise 185,000 square feet, will be consolidated into the Post Office space.

Hiring is expected to begin next year.

Uber Freight launched in May 2017 and recently expanded into Europe with an office in Amsterdam. It currently counts 400,000 drivers and 1,000 shippers in its domestic network, including AB Inbev, Niagara Bottling and Land O’Lakes.

“Chicago is the heart of America’s transportation and logistics industry, and there is no better place to open our dedicated freight headquarters,” Khosrowshahi said in a press release. “Uber has long recognized the incredible history, innovation and talent that Chicago has to offer, and we’re excited about the thousands of new jobs our freight business will help bring as we become one of the city’s largest technology employers.”

The company plans to spend $200 million annually on staff, real estate and expenses in Chicago.

The Old Post Office, which sits suspended over the entrance to the Eisenhower Expressway (Interstate 290), has been vacant for a quarter century. It has 2.7 million square feet over nine floors. Walgreens, the building’s first corporate tenant, leased 200,000 square feet. Ferrara Candy, ad agency AbelsonTaylor and meal-kit provider Home Chef also leased space. Pepsico and WeWork reportedly are finalizing leases.