Why was slavery an important issue for the new republican party ?

In many ways, slavery was THE issue for the new Republican party.

Many, if not most, historians see the Republican party as being formed as a coalition of interest groups opposed to slavery in the new Western territories (and soon to be states).

Divides in the early party were over what to do about slavery overall, but there was general agreement that slavery could not and should not expand into the western states.

on april 6, 1917, the u.s. joined its allies--britain, france, and russia--to fight in world war i. under the command of major general john j. pershing, more than 2 million u.s. soldiers fought on battlefields in france.