 By 1770 , the castle had fallen into disrepair , and many parts of it were demolished during the late 18th century and early 19th century . In 1787 all the gates in the city wall , except for Westgate — the city jail — were demolished as a result of a commission that found them impeding to new coach travel . Canterbury Prison was opened in 1808 just outside the city boundary . By 1820 the city 's silk industry had been killed by imported Indian muslins ; its trade was thereafter mostly limited to hops and wheat . The Canterbury and Whitstable Railway , the world 's first passenger railway , was opened in 1830 ; bankrupt by 1844 , it was purchased by the South Eastern Railway , which connected the town to its larger network in 1846 . The London , Chatham , and Dover arrived in 1860 ; the competition and cost @-@ cutting between the lines was resolved by merging them as the South Eastern and Chatham in 1899 . In 1848 , St Augustine 's Abbey was refurbished for use as a missionary college for the Church of England 's representatives in the British colonies . Between 1830 and 1900 , the city 's population grew from 15 @,@ 000 to 24 @,@ 000 . 
