What do historians do when they evaluate a source of information about the past? They find additional information about the event mentioned in the source.
They ask other social scientists about the accuracy of the source’s information.
They compare evidence in one source to evidence in another source.
all of the above

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

“well,” he says, “there’s excuse for picks and letting-on, in a case like this; if it warn’t so, i wouldn’t approve of it, nor i wouldn’t stand by and see the rules broke—because right is right, and wrong is wrong, and a body ain’t got no business doing wrong when he ain’t ignorant and knows better. it might answer for you to dig jim out with a pick, without any letting-on, because you don’t know no better; but it wouldn’t for me, because i do know better.” the meaning in this excerpt is

Why did william blackstone believe that parliament was important?