Although remaining largely farmland until the mid 20th century, initial transport links to the area began in 1848 with the building of the Liverpool and Bury Railway through Kirkby. The East Lancashire Road (A580 road) added road connections in 1935 and industrial development was being considered prior to the outbreak of the Second World War. A Royal Ordnance filling factory – ROF Kirkby – was established in 1939 and completed in 1941. At its peak, the factory employed over 20,000 workers.