I think it's because many of former slaves run to the northern region after the Civil war.
Beside that, the northern region of the united states were more socially, industrially, and economically advanced compared to the southern part
hope this helps
I think its C because America enters the war when German started sinking there merchants ships.
In the 1830s, several parties of Americans traveled to Oregon, further establishing the Oregon Trail. Many of these emigrants were missionaries seeking to convert natives to Christianity. Jason Lee was the first, traveling in Nathaniel Jarvis Wyeth's party in 1833 and establishing the Oregon Mission in the Willamette Valley; the Whitmans and Spaldings arrived in 1836, establishing the Whitman Mission east of the Cascades. In 1839 the Peoria Party embarked for Oregon from Illinois.
In 1841, wealthy master trapper and entrepreneur Ewing Young died without a will, and there was no system to probate his estate. A probate government was proposed at a meeting after Young's funeral. Doctor Ira Babcock of Jason Lee's Methodist Mission was elected Supreme Judge. Babcock chaired two meetings in 1842 at Champoeg (halfway between Lee's mission and Oregon City) to discuss wolves and other animals of contemporary concern. These meetings were precursors to an all-citizen meeting in 1843, which instituted a provisional government headed by an executive committee made up of David Hill, Alanson Beers, and Joseph Gale. This government was the first acting public government of the Oregon Country before American annexation.
