What is a federal system of government and how did this protect the states

In an effort to end the civil war, in 1864 the union planned to

Why is julius caesar considered an important roman leader? a. his assassination led to a civil war that ended the roman republic.b. his commitment to justice led to the creation of the twelve tablesc. his support for democracy led to expand voting rights for all romansd. his policies as dictator led to a period of peace known as the pax romana

Why are nation-states difficult to create?