The signal event that showed the need for a professional police force was the Peterloo Massacre of 1819. In the face of widespread poverty combined with the displacement of skilled work by industrialization, movements emerged across the country to call for political reforms. In August 1819, tens of thousands of people gathered in central Manchester, only to have the rally declared illegal. A cavalry charge with sabers killed a dozen protestors and injured several hundred more. In response, the British state developed a series of vagrancy laws designed to force people into “productive” work.
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