How was imperialism a cause of wwi?

Yes it is Did you learn MAIN causes of ww2

Simple. Imagine the world is a cake. Every European country wants a slice. Countries with fewer and/or smaller sizes grew envious. So when they saw a chance to stick it to the other, more powerful countries they took it.

Basically, it caused greed.

united states reinforcements contributed greatly to three allied victories in france at: cantigny (first major american battle), argonne (the largest in the united states military history, involving 1.2 million american soldiers), and château-thierry (one of the first actions under general pershing).