What do the California, Oregon, and Santa Fe trails have in common?

Why did some states believe they had the power to overturn federal laws?

What was the main cause of the russian revolution? a. the protests against the war with poland b. the tremendous war losses of world war 1 c. the protests against the treaty of brest- litovsk d. the losses dictated by the treaty of versailles

The eastern roman empire is also known as what empire