Why do historians rely on primary sources? ?

What effect did john hay’s open door policy letters have on the imperial powers of britain, france, germany, russia, and japan? a. it provoked the imperial powers to declare war on the united states. b. it caused the imperial powers to restrict trade in their trade with china. c. it warned the imperial powers that the united states would soon declare war on china. d. it signaled to those powers that the united states would take a larger role in world affairs than before.

Which best represents the view of the southern delegates at the constitutional convention

"august 19th (1864)- how they quarreled and wrangled among themselves- alabama and mississippi, all were loud for joe johnston, save and except the long-haired, one-armed hero, who cried at the top of his voice: "oh! you all want to be kept in trenches and to go on retreating, eh? " "oh, if we had had a leader, such as stonewall (jackson), this war would have been over long ago! what we want is a leader! " shouted a (wounded man). they were awfully smashed-up, objects of misery, wounded, maimed, diseased. i was really upset, and came home ill. this kind of thing unnerves me quite." mary chestnut, a diary from dixie this entry from the diary of mary chestnut illustrates a) the lack of medical technology possessed by the confederacy. b) the military superiority of southern troops in the civil war. c) the effects of the emancipation proclamation on the southern economy and society. d) the loss of morale and confidence by the confederacy towards the end of the civil war.