Not only is the Stonewall Inn now a national monument, it's the very first national monument dedicated to LGBTQ Americans.
New York police used a prohibition on selling alcohol to homosexuals as a pretext to raid the Inn in June of 1969, an action that sparked nationwide protest and marked a turning point for gay rights.
You can read the announcement in full at the White House website which reads in part:
The designation will create the first official National Park Service unit dedicated to telling the story of LGBT Americans, just days before the one year anniversary of the landmark Supreme Court decision guaranteeing marriage equality in all 50 states. Additionally, in celebration of the designation and New York City’s Pride festival, the White House, in coordination with the National Park Foundation and the Outdoor Advertising Association of America, is releasing a video that will be played on the billboards in Times Square on Saturday, June 25, beginning at 12:00pm ET.
The new Stonewall National Monument will permanently protect Christopher Park, a historic community park at the intersection of Christopher Street, West 4th Street and Grove Street directly across from the Stonewall Inn in Manhattan’s Greenwich Village. The monument’s boundary encompasses approximately 7.7 acres of land, including Christopher Park, the Stonewall Inn, and the surrounding streets and sidewalks that were the site of the 1969 Stonewall Uprising.
— The White House (@WhiteHouse) June 24, 2016