How to write the timeline of modern history?

The timeline of China's modern history is: June1840-September 1949.

From the outbreak of the Opium War in1June 840 to the establishment of People's Republic of China (PRC) in 1949+ 1 year1October. /kloc-The outbreak of the Opium War in 0/840 was a historical turning point in China's transformation from an independent feudal society to a semi-colonial and semi-feudal society, and it was also the beginning of China's modern history.

In the whole semi-colonial and semi-feudal society, the social nature of China determines the main contradiction, revolutionary object and task nature of China society.

The main manifestations of anti-aggression and anti-imperialism;

The national contradiction between the Chinese nation and foreign invaders constituted the "semi-colonial society" in modern China. After the major western capitalist countries completed the second industrial revolution and successively entered the imperialist stage, anti-aggression developed into anti-imperialism.

Anti-feudalism and seeking democracy are class contradictions between China people (including peasants, workers, craftsmen, bourgeoisie and petty bourgeoisie) and feudalism or feudal forces (including landlord class and bureaucratic bourgeoisie), which constitute a "semi-feudal society" in modern China.

Refer to the above content: Baidu Encyclopedia-Modern History of China