The First International, founded in London in 1864, was the first proletarian international organization and dissolved in the United States 12 years later.
In the 1850s and 1860s, the number of the proletariat doubled, the working classes of all countries became aware of the importance of unity and organization among themselves in the course of their struggles, and the First International was the result of the natural development of the proletariat.
In 1863, the Polish uprising fought against Russian rule and fought for national independence. The repression of Tsarist Russia provoked the anger of The British and French workers, who demanded that their respective parliaments rebuke Tsarist Russia and support Poland. The following year an international workers' organization was formed, which also became the inaugural congress of the First International. Marx was the soul of this organization, drafting programmatic documents such as the Declaration on the Founding of the International WorkingMen's Association and assisting the workers in various countries in their strike actions.
In the 1860s and 1870s, wars broke out between European countries, especially the Franco-Prussian War, and the street wars organized by the French working class against Prussian aggression were organized and supported by the First International. The French government at that time signed the surrender agreement, and the Paris workers organized the Paris Commune, organized the struggle, although it lasted only 72 days, but accumulated a wealth of experience for the workers' movement.
In the process, Marx also needed to fight against various ideas, such as Proudhonism (petty bourgeoisie), anarchism (Bakunin), etc. However, the persecution of the Comintern by European governments, fueled by separatism such as Bakunin, the First International moved to New York, usa, and later disbanded with decoupling from the workers' movement.
At its peak, the First International had 2 million members, laying the foundation for workers' activity. It also accumulated extremely valuable experience for the subsequent workers' movement.