Final answer:
During the Civil War, about 2.1 million men served in the Union army, and the Confederate army was smaller, not reaching 3 million. Women were generally restricted to noncombat roles, and African American soldiers did not serve in significant numbers in the Union until after 1863. The Union and Confederate forces were not the same size. The correct answer is option b. and c.
Step-by-step explanation:
During the American Civil War, both the Union and the Confederate armies relied on conscription and voluntarism to bolster their ranks. The vast enthusiasm at the war's outset soon diminished, leading to challenges in recruitment, which resulted in the passage of conscription laws in the South following advice from Robert E. Lee in March 1862.
While nearly 2.1 million men served in the Union army, it is not accurate that 3 million men served in the Confederate army. In terms of size, the Union forces were significantly larger than the Confederate forces throughout the war. Women contributed to the war effort primarily in noncombat roles, such as nursing, and only engaged in direct combat when disguised as men. In the Union, African American soldiers were not enlisted until after 1863, and their participation faced significant resistance. By the war's end, over 190,000 African Americans had served in the Union army and navy.
Overall, the Union and Confederate forces were not approximately the same size, as suggested in option d). Options a) and c) do hint at the number of men who served, but it's important to note that the approximation for the Confederate army is not as high as 3 million. It is correct that women served only in noncombat roles as b) indicates, although there were rare instances of women in combat roles when disguised as men.