The economic studies necessitated by his book "Capital" led Marx into the study of the social history of England during the eighteenth and nineteenth centuries, and gave him an insight into the working-class movements of those times such as but few scholars, English or foreign, have acquired. He became familiar with the modes of thought and expression of the working-class revolutionary movements, and especially of the Chartist movement, with the surviving leaders and adherents of which he was personally acquainted. Always eager to obtain knowledge of the actual working-class movement and to take part in it, he watched the activities of the English working class, which in the fifties was mainly occupied with purely trade unionist questions, being, politically, still in the Liberal camp. A change seemed imminent, however, about the beginning of the sixties. The London Labour leaders began to think about a Parliamentary reform movement, about starting a campaign for universal suffrage, which was an old Chartist demand. Likewise they manifested an interest in the fate of Poland and in other international questions concerning liberty. At the International Exhibition held in London in 1862, the Labour leaders made the acquaintance of a deputation of French working men, with whom they afterwards carried on a correspondence. In 1863 and 1864, in the course of this correspondence, the idea of founding an international union of workers was mooted; and in the fourth week of September, 1864, this idea was carried into effect. Labour delegates from Paris and London held a conference in London from the 25th to the 28th of September, and the event was celebrated by a public gathering in St. Martin's Hall on the evening of the 28th. Marx received an invitation to this meeting in order that the German workers might be represented there. This conference and meeting resulted in the formation of the International Working Men's Association. Committees and sub-committees were elected to draw up a declaration of principles and outline the constitution. One of Mazzini's followers and a Frenchman submitted schemes which were handed over to Marx to be elaborated by him. He consigned them to the waste-paper basket and wrote the "Inaugural Address," giving a history of the English workers since the year 1825, and deducing the necessary conclusions. The declaration of principles is entirely the work of Marx, and it is by no means a subtly and diplomatically conceived composition designed to please English and French working men; it consists essentially of Marxian ideas expressed in terms, however, which would appeal to English working men of that time. "It was difficult," writes Marx to Engels--("Correspondence," Vol. III., p. 191)--"so to arrange matters that our view should appear in a form which would prove acceptable to the working-class movement with its present outlook.... It needs time before the reanimated movement will allow of the old boldness of speech.