My answer is Louisiana purchase.
Because of the various technological and industrial advancement, there was huge growth of cities in America.
Explanation:
Many new possibilities if employment were opened in America which allowed many immigrants to occupy in order to have a better livelihood. Transatlantic railroad construction companies observed Asians to be the cheapest form of labor and many Chinese were employed in the construction of it. Urbanization in America led to the growth of busy commercial cities like Boston, New York and Philadelphia.
Textile mills and many sweat shops attracted the women workers too. Although, cities sprang up to be developed during the nineteenth century, it also paved way for many reform movements like labor union movements, women suffrage movements.
The main reason the United States government intervened in the Great Railroad Strike of 1877 was because it was leaving thousands of people without transportation, which meant that the US GDP was decreasing in hurting business of all kinds.
Papermaking, printing, gunpowder and the compass - the four great inventions of ancient China-are significant contributions of the Chinese nation to world civilization.
A suicidal action in order to harm the enemy. Kamikaze soldiers are prepared to give up their lives for their cause, often due to a belief that they will be honored in the afterlife because of it.
