In the first such use of his executive powers, President Trump on Friday designated a national monument, establishing a 380-acre site in Kentucky to honor African Americans’ role as soldiers during the Civil War.

The move won praise from local activists and conservationists but also criticism from several environmental groups, which noted that Trump used this same authority under the 1906 Antiquities Act last year to downsize two existing national monuments in Utah.

Republicans had pushed for more than a year to establish a national monument at Camp Nelson in Nicholasville, Ky., which served as one of the largest recruitment and training depots for United States Colored Troops. Although Kentucky was the last state in the Union to allow the enlistment of African American men, the camp sent 23,000 of the roughly 180,000 black troops who fought for the Union during the Civil War.

“During the war, thousands of enslaved African Americans risked their lives escaping to Camp Nelson, out of a deep desire for freedom and the right of self-determination,” Trump said in the proclamation he signed Friday.

Jim Fryer, a retired Navy senior chief petty officer and descendant of men who fought in the U.S. Colored Troops, said in a statement Saturday, “These are hallowed grounds here, let it be a park, let it remain a park."

Interior Secretary Ryan Zinke, who last year recommended that Trump designate the site as a national monument, celebrated the announcement Saturday in an event in Kentucky attended by dozens of activists and Rep. Garland “Andy” Barr (R-Ky.), who wrote legislation to recognize it.

“Camp Nelson, and all the patriots who have ties to it, holds an incredible place in America's history, and President Trump's action to designate Camp Nelson as a national monument will ensure the ongoing protection of the site and the story,” Zinke said in a statement, adding that he thanked the president “for using the Antiquities Act as it was truly intended.”

Barr hailed the news in a tweet Saturday, sharing photos of himself and Zinke at the ceremony. “I am proud to advocate for Camp Nelson, a site which has the ability to unite the American people,” he said.

Kate Kelly, director of public lands for the liberal think tank Center for American Progress, said the camp “deserves to be protected.” However, she questioned the timing of the proclamation, given that Barr is locked in a tight reelection race with Democrat Amy McGrath.

“But we can’t ignore the deep irony and injustice in President Trump using the same authority to protect one chapter of America’s story, while illegally stripping protections for another national monument that honors Native American history and culture,” she said, referring to Utah’s Bears Ears National Monument, which Trump shrank by 85 percent in December. “Given this announcement comes mere days before a tight election in Kentucky, we must also question whether the historic site is being used as a political pawn.”

Interior spokeswoman Heather Swift noted that the department invited all the members of Kentucky’s congressional delegation to Saturday’s event.

Alan Spears, cultural resources director in the National Parks Conservation Association’s government affairs office, said in a phone interview Saturday that the designation highlights the fact that there was a “great deal of Union sentiment in Kentucky” during the Civil War, even though the state now has dozens of Confederate monuments still standing.

“There has been a reversal of the actual sentiment of what Kentucky was during the war,” Spears said.

Kentucky initially declared neutrality during the war, but after Confederate forces attempted to seize the state, the legislature asked the Union army for assistance.