The Britannica Guide to Political and Social Movements

There is strength in numbers, which is why efforts to effect change that have plenty of support and high participation rates are the most likely to succeed. Such movements are formed when people organize with the goal of putting ideas into action, often in an attempt to bring about political or social change. As many successful political and social movements through the ages have demonstrated, groups with a well-thought-out agenda and clear goals can raise civilizations to new heights or bring them down, create empires or destroy them. They can radically alter the course of a nation and the lives of its citizens.