 By the 1850s, many steam-powered railways had reached the fringes of built-up London (which was much smaller than now).But the new lines were not permitted to demolish enough property to penetrate the City or the West End, so passengers had to disembark at Paddington, Euston, King's Cross, Fenchurch Street, Charing Cross, Waterloo or Victoria and then make their own way via hackney carriage or on foot into the centre, thereby massively increasing congestion in the city.The Metropolitan Railway was built under the ground to connect several of these separate railway terminals.