This page has information on some of the most significant political and social movements during the 1950s-1970s. Many of the lessons learned from these movements have helped lay the groundwork for today's activists. The articles linked are not in-depth or analytical but they will give you a good overview of the organizations, activities, personalities and issues involved. If you're looking for sources with analysis, use the databases to find books and articles that will go more in-depth.
March on Washington, 1963