During the 1800s, things changed alot because of industrialization. This was when countries started building big factories with machines. These machines could make stuff way faster than people could by hand. Because they were making so much stuff, they needed two things: more materials to build things and more people to buy them. This gave countries the "motivation" to go take over other places.

One big reason for imperialism was money. Factories needed raw materials like rubber for tires, oil for engines, and cotton for clothes. If a country didn't have these things at home, they just went to places like Africa or Asia and took them. They also wanted "new markets," which is just a fancy way of saying they wanted more customers to sell their factory goods to so they could get rich.

Another reason was politics and nationalism. Nationalism is when you think your country is the #1 best. Back then, countries like Great Britain, France, and Japan thought that having a huge empire made them look really powerfull. It was like a competition to see who could grab the most land on a map. They used their military and big navy ships to force weaker territories to let them be in charge.

Technology also gave them the "ability" to do this. Because of industrialization, they had better weapons and steamships. They could travel deeper into places they couldn't reach before. For example, the British took over India and used it for its resources. Another example is how European nations "scrambled" to divide up Africa for its gold and diamonds. A third example is how the United States started taking over islands in the Pacific to have places for their ships to stop.

In the end, industrialization gave powerfull countries the tools and the reasons to expand. They got rich and powerfull, but it was really bad for the indigenous people who lived there because they lost their land and their freedom.