in the eastern industrial communities of Canton and Highlandtown resisted and opposed annexation, but were annexed 30 years later. The last major annexation took place in 1918–1919, which again took territory from the county on all three sides (west, north, and east) as well as to the south for the first time from Anne Arundel County, along the south shores of the Patapsco River. A new Baltimore County Courthouse was authorized to be built facing Washington Avenue, between Chesapeake and Pennsylvania Avenues to replace the previous courthouse and governmental offices then centered for near 85 years in the city, which had been the official "county seat" since just before the American Revolution. Later surrounded by manicured flower gardens, shrubs and curved walkways, the historical landmark is built of local limestone and marble. It was completed and dedicated in 1855. Wings and annexes were added in 1910, 1923 and 1958. By the 1970s, the county's legal system and governmental offices had grown so much that a separate modernistic "County Courts Building" was erected to the west behind the old Courthouse with its annexes, separated by a paved plaza which is used for employee/visitors relaxations and official ceremonies. A constitutional amendment to the 1867 Maryland Constitution was approved by referendum in 1948, prohibiting any future annexations without approval from residents in affected territories. Extensive city-county hostilities came during the Civil Rights Movement, and by the 1980s the county's older inner suburbs faced increasing urban social ills. An atmosphere of cooperation emerged with the drawing of cross-border state assembly districts, organizing of regional government agencies, and increasing state assumption of powers. The county has a number of properties and sites of local, state and national historical interest on the National Register of Historic Places which is maintained by the National Park Service of the U.S. Department of the Interior by the "Historic Sites Act" of August 1935. Politics and government Baltimore County has had a charter government since 1956. The government consists of a County Executive and a seven-member County Council. The County Executive and Council members are elected in years of gubernatorial elections. The County Executive may serve a maximum of two consecutive terms. Without incorporated cities or towns, the county government provides all local services to its residents, many of which are normally associated with city-type governmental agencies. In 1956 the County adopted an "executive-council" system of government with "at large"