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.