The collection has developed over many years and has been acquired by purchase and donation. The bulk of these items were acquired in the 1970s from - so Library legend has it - a man in Leicester who had saved them from being burnt (the original source was possibly the British Rail Depot at Market Harborough though more recent study has suggested that the items may have been at the LMS (Midland Division) Estates Department). Most of these items are in classes Maps.RLY (smaller maps plus letters and other documents), Maps.RLY.aa (larger maps stored flat), Maps.RLY.R (large maps stored rolled) and Atlas.RLY (bound volumes of maps). However, some items at these classes have been acquired from other sources, something that will sometimes be recognised in a provenance note. Most of the class divisions reflect how the maps are stored but classes Maps.RLY.BWA, Maps.RLY.DC and Maps.RLY.Z reflect the donor of the items. Additional railway maps (printed and manuscript) can be identified by looking at the Map Department’s card catalogue and at iDiscover, the Library’s online catalogue. See our Blog Post about the collection at https://specialcollections-blog.lib.cam.ac.uk/?p=1876 Or see the pdf lists at: https://www.lib.cam.ac.uk/files/rly_all_except_i_introductory_level_descriptions_21_nov_2019.pdf (Maps.RLY items arranged by railway company/author and then date) and https://www.lib.cam.ac.uk/files/rly_companies_all_21_nov_2019.pdf (Maps.RLY railway companies/authors only).