Search london history from Roman times to modern day
A bit out of date, but this interactive map of step free London is very good
All the London railway stations :
National Rail : ThamesLink
Accessibility friendly : Step-free access to both platforms via side gates. Mobility-impaired customersare advised tobook in advance. Step-free route between platforms via street. Step-free access to Ticket Office from street, but steps from Ticket Office to platforms.
General description : See wiki
More comment : National Rail Map & Guide.