The Federal Building is a historic structure in Gettysburg, Pennsylvania. It was erected in 1913, the 50th anniversary year of the Battle of Gettysburg. The main building since 1992, it previously served as the War Department/National Park Service headquarters of the Gettysburg National Military Park from 1912 to 1962 and as a branch of the United States Post Office. In 2014, the Adams County Library System celebrated the building's 100th anniversary with three days of community events.