Notes:  "Railway Mania", the speculation that led to 248 railway Bills before Parliament in the single year of 1845, had ended by 1847, but the tremendous increase in railway lines that resulted (by the companies that avoided bankruptcy) took until 1850 to be fully visible. The first serious competition, as the railway companies grouped themselves in to ever larger groupings, began in this period. The LSWR and LBSCR fought over Portsmouth, eventually both building lines to connect it to their network. The GWR expanded ever westward (and most other directions), bringing Plymouth, Exeter, Cardiff, Swansea, Oxford, Gloucester, Birmingham (Snow Hill), Shrewsbury, Chester and Birkenhead within its domain. The London & North-western Railway (LNWR) reached Carlisle, linking to Edinburgh, Glasgow and Ayr via new lines; they also reached Holyhead to provide the primary link with Ireland, then still an integral part of Britain. From York a fast route north to Edinburgh was built, continuing on to Aberdeen, initially via an inland route through Forfar. Southward York was connected to London, but by a rather indirect and intricate route. Large numbers of lines were built to interconnect the manufacturing towns of the Midlands and South Pennines, many towns being (?)served by several competing companies. The Great Northern Railway (GNR), heading due north from King's Cross, had reached Peterborough (the fifth line to do so) and continued to Doncaster via a tour of Lincolnshire. In East Anglia, Norwich was reached first via Cambridge, and shortly later via Ipswich.