Britain’s railways were built mainly in the second and third quarters of the nineteenth century by companies operating under private Acts of Parliament. However, Parliament began to intervene in the running of the railways in the Railway Regulation Acts of 1840, 1842 and 1844, which amongst other things led to the beginning of state regulation of railway charges; while rail accidents led to the establishment of HM Inspectors of Railways to ensure passenger safety. By 1914, after a number of mergers, the railway network was operated by 123 railway companies providing 23,000 route miles. During the First World War the railways came under state control and immediately afterwards nationalisation was considered, although rejected. Instead, the Railways Act 1921 resulted in consolidation into four private sector regional companies. The Second World War led to another period of state control. Nationalisation of the railways had been a Labour Party objective since 1908, and with a majority Labour Government elected in 1945, the industry was nationalised on 1 January 1948 as British Railways (BR), a subsidiary of the new British Transport Commission (BTC). The decision to nationalise was supported by the railway trade unions and by those who expected the result to be improved services. BR became a separate public corporation with its own board when the BTC was dissolved in 1962.