Why did modern tourism develop in the middle of19th century? More than 600 words is preferred.

Modern tourism began in the middle of19th century. The main reason for the modernization of tourism is that the industrial revolution tourism has turned into a popular social activity, and enterprises serving tourism have formed independent industries and existed as independent economic departments, which is still a matter of nearly a hundred years. If 1840 is regarded as the gathering place of ancient tourism dome and modern tourism. As a result of the Opium War of 1840, China was carved up by the great powers and became a semi-colonial and semi-feudal society. Modern tourism is basically in a state of stagnation. At this stage, western tourism is in a period of great development. (1) The era of mass tourism in the west has gradually taken shape. 19th century is the period when the capitalist system in Europe and America was established. With the vigorous development of the industrial revolution, the whole social economy is in remarkable development. At that time, steam engines and railways developed rapidly. With the development of mass production of social machines, the urban population has increased rapidly, people have gradually become rich in time and economy, and the number of tourists has also increased rapidly. From 65438 to 0845, the first commercial travel agency founded by Englishman Thomas Cook was born, which became the symbol of the birth of modern tourism. Tourism service has become an independent industry, tourism activities are changing to social activities with public participation, and tourism in western China has entered a period of great development. (2) After1840, the modern tourism industry in China was at a standstill. After years of war, all industries are dying, and the people of China are in a poverty-stricken situation of hunger and cold, and they don't take part in tourism at all. Therefore, until 100, before the founding of New China, China's modern tourism was on the verge of stagnation, only near the coastal concessions, and a small number of them were used by warlords, bureaucrats and foreign adventurers for summer vacation. In addition. Some revolutionary sites for people to visit have become important tourism resources in modern tourism history. Such as Sanyuanli, Nanjing Taiping Heavenly Kingdom Memorial Hall, Huanghuagang 72 Martyrs' Tomb, Sun Yat-sen Memorial Hall, Sun Yat-sen Mausoleum, the site of the first congress in China, the former site of the "August 1st" Nanchang Uprising Command, Jinggangshan, Zunyi, Yan 'an, Xi Incident, Northeast Martyrs Memorial Hall, Lugouqiao, Pingxingguan and Taierzhuang, as well as Shaoshanchong in Xiangtan and Hongyan Village in Chongqing. The first travel agency in modern China was the Travel Department affiliated to Shanghai Commercial Reserve Bank, which was established in 1923. 1927 changed to China travel agency. It is 80 years later than western tourism, with little business, but it has existed for several years.