President Donald Trump’s recent White House renovations are moving into the historical building’s East Wing.

Photos of a bulldozer tearing through the wing’s facade went viral on social media this week, sparking criticism from historical societies and some political figures.

The National Trust for Historic Preservation, a Washington, D.C.-based nonprofit, said it was "deeply concerned" about the planned construction in an Oct. 21 open letter to the National Capital Planning Commission, the National Park Service and the Commission of Fine Arts

"We respectfully urge the administration and the National Park Service to pause demolition until plans for the proposed ballroom go through the legally required public review processes, including consultation and review by the National Capital Planning Commission and the Commission of Fine Arts, both of which have authority to review new construction at the White House, and to invite comments from the American people," the organization wrote.

As construction continues, here’s what to know about the East Wing of the White House.

What is the East Wing of the White House?

A large structure that originally began as a colonnaded terrace during President Thomas Jefferson’s administration, the East Wing has served as office space and has held a theater and a visitor’s entrance, according to an archive of the White House's website.

White House visitors often entered through the White House’s east entrance and followed the East Colonnade past the former Rose Garden, which was renovated earlier this year, to enter the residence and see rooms on the Ground and State Floors.

When was the East Wing built?

The modern version of the East Wing was added to the White House in 1942. The terrace that existed in Jefferson’s time was removed in 1866 and rebuilt on the foundation in 1902. Prior to 1942, a greenhouse occupied the east grounds of the White House, according to an archive of the White House’s website.

In 1942, President Franklin D. Roosevelt further developed the East Wing to house additional staff and offices, according to the White House Historical Association.

The construction was highly controversial at the time because it took place during World War II, the association’s website states. Republicans in Congress called the project "wasteful," and some accused Roosevelt of "using the project to bolster his presidency’s image."

According to History.com, Roosevelt originally constructed the building to cover up an underground bunker that would protect the president and his staff from an enemy attack during World War II.

Where is the East Wing located?

The East Wing is connected to the main residence of the White House by a covered colonnade and projects eastward from the main building.

What is the East Wing used for?

As of this year, the East Wing continued to serve as part of White House tours and had a gift shop. It had been the traditional location for the first lady’s offices until demolition began this week. White House Press Secretary Karoline Leavitt has said the first lady's offices have been temporarily relocated.

Why is the East Wing being demolished?

Part of the East Wing is being demolished to make way for a new $250 million White House ballroom. The ballroom will be a 90,000 square-foot addition to the White House, one of the biggest changes in decades. The White House has said the project is being privately funded, according to previous USA TODAY reporting.

The project "will significantly increase the White House’s capacity to host major functions honoring world leaders, foreign nations, and other dignitaries," the White House said in a statement.

Contributing: Janet Loehrke, USA TODAY

Michelle Del Rey is a trending news reporter at USA TODAY. Reach her at mdelrey@usatoday.com

This article originally appeared on USA TODAY: What is the East Wing? Demolitions underway at White House space

Reporting by Michelle Del Rey and Janet Loehrke, USA TODAY / USA TODAY

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