Friends of the Parks, a 40-year-old nonprofit dedicated to the preservation of Chicago’s parks and lakefront, has warned that it may sue President Barack Obama and his wife Michelle if they decide to place the Obama presidential library on parkland in either Washington Park or Jackson Park. The group issued this threat in a letter on February 16.

The letter, written by Friends of the Parks President Cassandra Francis, Board Chair Lauren Moltz, and Board Vice-Chair Fred Bates, resulted from the Chicago Park District’s February 11 decision to transfer about 20 acres of parkland to the city for $1 if the Obamas select the University’s bid for the Obama presidential library.

“We appeal to your thoughtful judgment, as a former local community organizer and international leader who represents and espouses equality and change, that a potential lawsuit is not the foundation upon which to build an institution which represents the legacy of your life’s achievements,” they wrote.

The letter proposes that the University of Chicago-owned “mostly vacant 11-acre, non-park site on the west side of Dr. Martin Luther King, Jr. Drive” serve as the library site instead.

The authors argued that parks serve a critical role in the city’s ecosystem by providing open spaces within the dense city.

“It is difficult to comprehend that in a neighborhood where parks and open spaces function as the ‘lungs of a city,’ providing respite from high-density urban development and where communities come together, that you would consider the confiscation of this important public open space asset as a construction site,” the authors wrote.

The letter concludes by urging President Obama to “make the right choice” and honor “our city and the ideals [he has] inspired in its people.”

The Obamas are expected to announce their decision by the end of March.