Selma is a city in and the county seat of Dallas County, in the Black Belt region of south central Alabama and extending to the west. Located on the banks of the Alabama River, the city has a population of 20,756 as of the 2010 census.The city is best known for the 1960s Selma Voting Rights Movement and the Selma to Montgomery marches, beginning with "Bloody Sunday" in March 1965 and ending with 25,000 people entering Montgomery at the end of the last march to press for voting rights. This activism generated national attention to social justice and that summer, the Voting Rights Act of 1965 was passed by Congress to authorize federal oversight and enforcement of constitutional rights of all citizens.It had been a trading center and market town during the years of King Cotton in the South. It was also an important armaments manufacturing and iron shipbuilding center during the Civil War, surrounded by miles of earthen fortifications.