NEW YORK (Reuters) -- A historical group on Friday began preserving thousands of sticky notes placed on the walls of a busy New York subway station over the past month to lament the election of Donald Trump as the next US president.

Distraught and defiant residents and visitors to the United States’ largest city -- long a Democratic and liberal stronghold -- have stuck anonymous messages on the walls of Manhattan’s Union Square station since Trump’s Nov. 8 victory. Many of the notes express grief or pledge to turn the country in a more liberal direction.

The New-York Historical Society removed 5,000 of the messages on Friday, putting them between plastic sheets and archiving them in boxes for undetermined future uses.

“We are ever-mindful of preserving the memory of today’s events for future generations,” the society‘s president, Louise Mirrer, said in a statement. “Ephemeral items in particular, created with spontaneity and emotion, can become vivid historical documents,” she said.

The society has preserved reactions to other major events, including the legalization of same-sex marriage and the Sept.11, 2001, attack on the World Trade Center.

The sticky-note installation, known as “Subway Therapy,” was the idea of a local artist who brought blank notes and pens to the station under Union Square.

In seeking to preserve a variety of notes, workers took all the ones from a 6-meter span of wall that had some of the earliest messages posted after the election, said Margaret Hofer, museum director at the New-York Historical Society.

The society may display the sticky notes in the future, although not while the project is still active on subway station walls. “To recreate it in a museum setting now is perhaps a little premature,” Hofer said.