There have been two separate generations of trams in London, from 1860 to 1952 and from 2000 to the present. There were no trams at all in London between 1952 and 2000.
A London Tramways horse tram, c 1890
The first electric tram on Kingston Bridge, 1906
A horsecar, horse-drawn tram, horse-drawn streetcar (U.S.), or horse-drawn railway (historical), is an animal-powered tram or streetcar.
The first horsecar in Manchester, New Hampshire, dating from 1877, and on display about 1908.
The Swansea and Mumbles Railway ran the world's first passenger tram service in 1807
London Tramways two-horse tram, about 1890.
London horse tram in the London Transport museum