The Marshall plan helped in stopping the communist aggression and expansion in Europe during the Cold War by establishing a global trade wherein it emphasizes "free market" and "encourage European peace." The plan helped to economically sustain and stabilized the war-torn countries in Europe.
The Kansas-Nebraska act allowed the people to vote if wanted to allow slavery in those states and this act served to appeal the Missouri Compromise. The Missouri Compromise prohibited slavery in the north. This act was also said to be a failure because it was made to end the conflict over slavery, but resulted in Kansas becoming a "battleground over slavery."
D. The United States Constitution, it holds the basic laws of our nation, "land"
The purpose for organizing labor unions is to help protect the rights of the workers.