Henry Ford was the first man to create the concept of the assembly line. This was when every employee was responsible for assembling only one part on Ford's cars. The assembly line was able to ramp up production and turned thousands of cars every month which resulted in more profits for Ford.
The United States rejected the Treaty of Versailles and negotiated its own peace agreement or agreement to end the war with Germany in 1921. The Senate would not vote to pass the Treaty of Versailles and instead sought to create a treaty or agreement solely based upon American terms.
It allowed you to understand what people and what things were like back then it also allows you to feel and experience what was going on through the time period your studying.