London was the incorporated as a city in January of 1855. Murray Anderson, a tinsmith, was elected as the first mayor.
In 1857 it seemed that London's prosperity was to be wiped out by depression. But in 1861 London’s economy was rescued by the American Civil War. Located in a rich agricultural belt, the city was soon shipping wheat to supply the Northern Army.
Affluence was soon evident in London's physical appearance. The erection of large downtown buildings began again. By the mid 1870's the centre of the city had assumed the shape it retained up until the 1960's. The decade of the 1870's also saw new mansions rising along Queens and Grand Avenues, visible evidence of the city's new found wealth. New institutions, such as the London Psychiatric Hospital and St. Joseph's Hospital were created. Huron College was established in 1863 and the University of Western Ontario in 1878.
Local financial institutions were founded in 1864. The merchants of the city formed Huron & Erie, their own trust company. London Life Insurance Company was founded in 1874. The communications of the city were again being extended, both internally and externally. The London Street Railway began in 1873 and the modernization of the bridges began with the construction of the Blackfriars Bridge in 1875. From 1871 to 1875 the London, Huron & Bruce Railway was constructed outside of the city .The present Canadian Pacific tracks were built across the city a decade later.
From this prosperous period, until the end of the century, London grew in size. Several of London's suburbs were annexed - London East in 1885, London South in 1890 and London West in 1898. Pottersburg, Ealing and Chelsea Green followed in 1912. In 1914, on the eve of World War I, London had reached a population of approximately 55,000 people.
From 1918 to 1939, the city continued to grow, although it was affected by the great depression. Several large buildings were constructed in this period. The Dominion Public Building on Richmond Street, the first buildings on the campus of the University of Western Ontario, the Bell Telephone Building on Clarence Street and the London Life Insurance Company offices on Dufferin Avenue. Many new homes were built in South London and in the Huron Street area.
Since the end of World War II, London has experienced tremendous growth .With a major annexation in 1961, which added 60,000 people to the city, London had grown close to a quarter of a million people in 1976.
London is now Canada’s 10th largest city with a population of 352,395.