The Louisiana Purchase gave the United States direct access to ; British Columbia.
; the Northwest Passage.
; the Appalachian Mountains.
; the Gulf of Mexico.

i think the gulf of mexico

Explanation:

is definitely not british columbia

one of the main reasons was definitely slavery. back in 1861, republican abraham lincoln was elected and ended up being a major influence in the slavery business. slavery greatly affected the texas economy because back in 1845 during the annexation of texas, slaves became a big part of the texas population. many texans that were in favor of the secession influenced groups through party ties.