President Barack Obama on Thursday designated three new national monuments devoted to civil rights history, including the first National Park Service site dedicated to Reconstruction, the still-contested period following the Civil War which featured the advance, and then the sometimes violent rollback, of citizenship rights for African-Americans.

Two of the monuments commemorate civil rights history of the 1950s and 1960s. The Birmingham Civil Rights National Monument will protect the A. G. Gaston Motel in Birmingham, Ala., which at one point served as the headquarters for the Rev. Dr. Martin Luther King Jr. during the campaign leading up to the Voting Rights Act, and link the motel to other sites in that city. The Freedom Riders National Monument in Anniston, Ala., will include the Greyhound Bus Station where a racially integrated bus of Freedom Riders testing desegregation was attacked in the spring of 1961, and the site where the same bus was firebombed and burned some minutes later.

The Reconstruction monument includes several sites near Beaufort, S.C., which fell under control of the Union Army in November 1861, and became one of the first places where emancipated slaves voted, bought property and created churches, schools and businesses.

Mr. Obama, in a statement, said that all three new monuments together represented “critical chapters in our history,” which he connected to one another as well as to National Park Service sites created during his tenure to honor advances in women’s and gay rights.