A dispute over 19th-century texts and old map boundaries added a legal argument to the ongoing struggle over the future of the Corcoran Gallery of Art. (Astrid Riecken/For The Washington Post)

A dispute over 19th-century texts and old map boundaries added a legal argument to the ongoing struggle over the future of the Corcoran Gallery of Art, as arts advocates charged Tuesday that any decision to move the gallery to the suburbs would violate the Corcoran’s charter.

The meaning of the original 1869 deed and the 1870 congressional charter establishing the gallery is “unequivocal,” said Andrew Tulumello, co-partner in charge of the Washington office of Gibson Dunn & Crutcher, a law firm representing the advocacy group Save the Corcoran. “Under any interpretation of the words ‘Washington City,’ it does not mean ‘Alexandria.’ ”

Corcoran executives, who announced in June that the financially struggling gallery must consider selling its historic home on 17th Street NW near the White House and perhaps moving, declined Tuesday to offer their own interpretation of the charter.

“We are reviewing the letter and discussing it with our counsel,” Mimi Carter, senior director of communications, said in an e-mailed statement. “Because we only received the letter late [Tuesday] morning, and there had been no prior discussion about its assertions even though the Corcoran has met with ‘Save the Corcoran’ and held no fewer than three community meetings, we are surprised and distressed by the many false statements and inaccuracies in the letter.”

Since June, the Corcoran has been crafting a plan to better integrate the gallery and related Corcoran College of Art & Design, reviewing offers to buy the building and scouting possible locations. Fundraising in recent years has plummeted, and annual deficits are $7 million. Corcoran officials have set no date to announce concrete plans.

Ensuring that nonprofit organizations in the District do not operate in violation of their charters falls to the office of D.C. Attorney General Irvin B. Nathan. A spokesman for Nathan said the office is monitoring the Corcoran’s planning but had no further comment.

The charter allegations are contained in a wide-ranging nine-page letter that Tulumello sent to Corcoran executives. The letter summarizes what Tulumello said was an “extensive factual investigation” — including a claim that Corcoran executives investigated sites on the Alexandria waterfront last year. In addition to raising the charter issue, the letter blames the Corcoran’s financial straits on mismanagement; disputes the need to consider moving; and questions whether the Board of Trustees is fully aware of the administrative actions taken by gallery President Fred Bollerer, Chairman Harry Hopper and chief operating officer Lauren Garcia.

“We reject all false and unfair accusations about the Corcoran and its trustees, officers and staff,” Carter said in the statement.

The letter demands that the Corcoran stop spending money and staff time exploring a move that would allegedly break the District’s law governing nonprofit organizations. And it calls for the Corcoran to add three trustees approved by Save the Corcoran to the 14-person board. The advocates set a deadline of Oct. 19 for the gallery to respond.

“This letter is an opportunity for them to do the right thing, and to bring in stakeholders to help them solve the problem,” said Tulumello, whose firm is representing Save the Corcoran for free. “They should think long and hard before turning it down.”

Save the Corcoran is a group of artists and arts advocates that formed shortly after the Corcoran announced plans to consider moving.

“Before the board can make the decision to sell the crown jewel of the D.C. art world, we need to make sure everyone, including the trustees, who many not have been completely informed of all these acts, are aware of the facts,” said Jayme McLellan, a founding member of the group and director of Civilian Art Projects, a local gallery.

The trustees are fully informed about administration of the gallery, said one member of the board who spoke on the condition of anonymity because Corcoran executives have asked trustees not to speak to reporters.

“The trustees are very aware of all legal obligations . . . and the details of the charter,” said the trustee. “I can’t believe that Harry and Fred have any scheme up their sleeves.”

The trustee added, “I think it’s important that we stay in the building.” At the same time, the trustee said, museums are under pressure and alternatives must be studied. “I think I can embrace a new future. I will do whatever’s best for the Corcoran.”

On May 10, 1869, financier William W. Corcoran affixed his seal to a property deed to permit “the execution of a long cherished desire to establish an institution in Washington City, to be dedicated to Art, and used solely for the purpose of encouraging American genius.”

For a sale price of $1, the deed transferred Corcoran’s personal art gallery at Pennsylvania Avenue and 17th Street NW — the building that now houses the Renwick Gallery — to the nine men who would become the Corcoran gallery’s founding board of trustees. The following year, Congress chartered the gallery.

The deed and charter traveled with the Corcoran in 1897 when it moved from the Renwick building three blocks south to a newly constructed beaux-arts masterpiece that remains its home. The Corcoran pioneered the presentation of American art and the public assessment of evolving art movements. But in the latter part of the 20th century, it was eclipsed by the National Gallery of Art and Smithsonian collections.

Coming as it does in a preamble section of the deed, the description of Corcoran’s “long cherished desire” for a gallery “in Washington City” might sound to modern ears like a rhetorical flourish, before the document gets down to the business of listing the “intents and purposes.” Those intents and purposes detail gallery operations and the powers of the trustees but say nothing about location.

Tulumello, however, said the reference to the founder’s cherished desire is legally binding. And “Washington City” had a particular meaning at the time. It described the portion of the District south of Florida Avenue, between the Potomac and Anacostia rivers. Thus, the Corcoran could not move to Maryland, or, for that matter, to Columbia Heights or Anacostia, he said.

Efforts to explore a possible move outside those boundaries are improper, he said.

“When any company — for-profit or nonprofit — spends money on something that would be illegal to do, then it is engaged in corporate waste,” Tulumello said.

Lonnae O’Neal Parker contributed to this report.