The correct answer is: 1. Many free African-Americans volunteered to fight for the Union.
The Emancipation Proclamation, issued by President Abraham Lincoln in 1863, declared that enslaved people in the Confederate states were to be set free. While it did not immediately free all enslaved individuals, it did allow for the enlistment of African-American soldiers in the Union Army, and many free African-Americans responded by volunteering to fight for the Union cause.