CHICAGO -- Seven years after filing the paperwork, Wrigley Field is to be given federal landmark status in the National Register of Historic Places, according to sources. The move will give owners of the Chicago Cubs, the Ricketts family, access to federal income tax credits on the recently completed refurbishing of the 106-year-old ballpark. The official announcement is expected Thursday.

Wrigley Field was built in 1914 but had not had an extensive makeover until the past half-decade when the Ricketts family spent about $1 billion of their own money to refurbish it. They applied for the federal status back in 2013, after becoming eligible for it in 1987, but needed to keep that eligibility through the renovations before being approved. The move should earn millions in tax credits, just as it did for the owners of the Boston Red Sox, who made a similar move with Fenway Park about a decade ago.

The Ricketts family abandoned their desire for taxpayer assistance in the renovations long ago but were hopeful to get the credits in the form of the landmark status, which was approved by the U.S. Secretary of the Interior, David Bernhardt.

"The historical significance of Wrigley Field is interwoven into our nation's story and a key part of what has become America's beloved pastime for over a century," Bernhardt said.

National Historic Landmarks are defined as "buildings, sites, districts, structures, and objects that have been determined by the Secretary of the Interior to be nationally significant in American history and culture." As such, certain renovations to said landmarks can qualify for tax credits. The Ricketts family upgraded the basic structure of Wrigley Field but modernized it, adding video scoreboards along with new seats and underground clubs. They also made it safer for fans watching in-stadium, as previously nets hung to catch falling debris from the aging structure.

Not all facilities survive their landmark status after renovations. Soldier Field, also in Chicago, was stripped of its landmark status in 2006 after it was rehabbed.

Wrigley Field is the second-oldest ballpark in Major League Baseball behind Fenway Park and was the home of the Chicago Bears from 1921 to 1970. There are approximately 2,600 National Historic Landmarks in the United States, including Fenway Park and the old Tiger Stadium.