The Association of Minor Railway Companies (AMRC) was created under the direction of the Derwent Valley Light Railway in 1938 as a successor to the Association of Railways of Local Interest (1929) and the Association of Minor Railways (1907) (AMR). The AMR was promoted by Col. Holman F. Stephens in 1907 to provide a platform for mutual support and a coordinated voice in government for Britain’s independent minor railway companies.

The government’s jurisdiction over minor railways passed to the newly-created Ministry of Transport in 1919, which sought to reorganise Britain’s railways through the grouping of railway companies into the ‘Big Four’ concerns: the Great Western; London Midland and Scottish, London and North Eastern and Southern Railways. The AMR, under the direction of Col. Stephens, successfully campaigned to remove minor railways from the grouping proposals, which were ultimately enacted under the Railways Act, 1921. Despite further representations in government to secure the interests of the minor companies after grouping, no further independent railway companies were created.

The AMRC was convened by the Derwent Valley Light Railway in 1938 to provide a collective response to the continuing expansion of road transport. This decision was also prompted by the intense collective lobbying undertaken by the ‘Big Four’ railway companies through the ‘Square Deal’ campaign, which attempted to improve the competitive position of Britain’s railway through the removal of anti-monopolist rate and traffic restrictions set by successive governments during the nineteenth century.

Although the AMRC met occasionally to discuss the effect of railway nationalisation upon its members in 1948, it ceased to convene from 1952. In 1970, Alan Garraway, General Manager of the Ffestiniog Railway approached Jim Acklam, General Manager of the Derwent Valley Light Railway with a view to reactivating the organisation to provide an organisation which could support the interests of existing and nascent independent railway preservation schemes in relation to publicity, sharing of expertise and parliamentary representation on matters of policy. Although several of the original member railways had ceased to operate, new members consisted of emerging heritage railways.

Other activities included negotiations with the Post Office and British Rail in 1974 concerning the continuation of the Railway Letter Service. This service permitted the posting of letters at railway stations for conveyance by train until it could be posted at a location near to the addressee for an extra charge. The AMRC became the Association of Independent Railways (AIR) in 1988.