Final answer:
Four slave states - Delaware, Maryland, Missouri, and Kentucky - did not join the Confederate States of America.
Step-by-step explanation:
Four slave states - Delaware, Maryland, Missouri, and Kentucky - did not join the Confederate States of America during the American Civil War. Although these states were slaveholding states, they remained in the Union and were referred to as border states. They were located geographically between the Union and the Confederacy, and their decision to remain loyal to the Union had strategic implications.
For example, Maryland's location near Washington, D.C., was crucial for the Union's defense, while Kentucky's neutrality ensured that the Union would maintain control over the strategically important Ohio River.
So, the statement that these four states did not join the Confederate States of America is true.
Learn more about Participation of certain states in the Confederate States of America