The process by which the collaboration between Bismarck and the National Liberals came to an end was long drawn out. Even before the collapse of the boom in 1873 shook a central pillar of liberalism, free trade and free markets, what in Germany was often called Manchesterism, was under attack from many quarters. Official policy, under the guidance of Delbrück, was still driving towards freer trade and the last protective tariffs on iron were removed only on 1 January 1877. In the meantime powerful industrial pressure groups were being organized, which first were concerned to halt the remaining moves towards free trade and then increasingly turned to protection as a means of combating the depression. The most important of these was the Central Association of German Industrialists (Centralverband deutscher Industrieller) founded in February 1876. It was a feature of the slump and the collapse of prices that industry was driven to rely increasingly on exports to maintain production. The overall index of export volume in Germany’s foreign trade rose from 17.7 in 1873 to 26.1 in 1878 (1913 = 100), a fifty per cent rise. In some sectors the rise was particularly striking, for example exports of iron and steel goods rose between 1876 and 1878 from 807,000 tons to 1.3 million tons. Representatives of the iron and steel industries admitted before a Bundesrat enquiry of 1878 that they were resorting to dumping. The debate over protection and free trade became nationalistic and there was much talk of protecting national labour. To the protectionist voices coming from many sectors of industry were added those of the agrarians, who had hitherto, particularly the bigger landowners of East Elbian Prussia, been firmly in favour of free trade. These bigger, often Junker, landowners were in fact not in the van of the agrarian demand for protection, for they did not feel the threat of overseas competition until the middle 1870s. It is therefore somewhat premature to speak of an alliance of ‘iron and rye’ in favour of protection. It was rather the smaller agricultural producers in the vicinity of developing industrial and urban areas who initially wanted to see their home markets protected.