Why did the Knights of Labor go abroad and set up assemblies in Britain and Ireland? Comparing the British and American labour movements over the course of the nineteenth century, this chapter argues that the 1880s was a unique decade: the victories and success enjoyed by American Knights and other American reformers attracted great interest in Britain, where the labour movement faced numerous problems and challenges. It then finds two major reasons behind the internationalism of the Knights of Labor: first, the idea of Universal Brotherhood, with deep roots in American fraternal and political traditions, and second, fears over mass immigration which seemed to require an international response. This chapter notes the important role of glassworkers in the Order’s international history, their creation oo the Universal Federation of Window-Glass Workers, and ends with the opening of the first assemblies on English soil.