Please someone help me

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

Identify the reason each country wanted to go to war in the year before and during world war 1

The fourteenth amendment how did the action resolve a longstanding conflict in post-civil war america? it defined the process for readmittance of the former confederate states into the united states of america. it ensured the right to vote to all male citizens of the united states, regardless of race, color, or prior servitude. it defined citizenship and related rights for african americans. it abolished slavery in the united states.