Since you use the term "slave state" I assume you mean at the start of the civil war. They all were states by 1861. The US went from East coast to West coast.
The balance of free and slave states in the senate was such an important issue because if the either had an advantage it would only help to trigger a war that was yet to come.
It was briefly a Confederate Territory until the US Army's California Column drove the CSA out.
The US wasn't attacked (yet).
YASS: Yet Another Slave State, as it was south of the Mason-Dixon Line, thus automatically making it slave. avioding competition in the cotton market
YASS: Yet Another Slave State, as it was south of the Mason-Dixon Line, thus automatically making it slave. avioding competition in the cotton market
YASS: Yet Another Slave State, as it was south of the Mason-Dixon Line, thus automatically making it slave. avioding competition in the cotton market
YASS: Yet Another Slave State, as it was south of the Mason-Dixon Line, thus automatically making it slave. avioding competition in the cotton market
YASS: Yet Another Slave State, as it was south of the Mason-Dixon Line, thus automatically making it slave. avioding competition in the cotton market
Before the Civil War, Texas, Arkansas, Louisiana, Missouri, Mississippi, Alabama, Georgia, Florida, North and South Carolina, Kentucky, Tennessee, and Virginia (West Virginia was not an independent state yet) allowed slavery.
Technically they were, (usually) the northern states of the USA (north of the Ohio river). Yet, the Dred Scot decision by the USA Supreme Court really meant the entire USA was a slave nation prior to the Civil War. Dred Scot was a slave taken to a "free" state, and he argued for his freedom, but, the Supreme Court ruled that no matter where he was taken, Dred Scot was still a slave.
The Rt Hon Arthur Neville Chamberlain.
Three states, Kentucky, Maryland, and Missouri were slave holding states but did not join the Confederacy. Each of these states have complex reasons for remaining in the Union and yet retained their slaves. Tennessee was a slave state and joined the Confederacy. The latter was late, joining the South in May of 1861.