Final answer:
The true statement about the Emancipation Proclamation is that it freed slaves in states in open rebellion against the Union, based on military necessity. It did not immediately free all enslaved individuals in the Confederacy and did not apply to loyal Union states or Confederate areas under Union control.
Step-by-step explanation:
Limitations of the Emancipation Proclamation
The Emancipation Proclamation, issued by President Abraham Lincoln on January 1, 1863, was a significant wartime measure with specific limitations. It is important to understand that: it did not immediately free all enslaved individuals in the Confederacy, particularly because Union forces could not enforce it in areas they did not control. Moreover, the Proclamation applied only to Confederate territories in rebellion and not to loyal Union states, leaving slaves in the Border States and certain Union-occupied regions still in bondage. The Proclamation also did not apply to Confederate areas already under Union control, like Tennessee and parts of Louisiana and Virginia.
Therefore, the correct answer to the question of which statement is true of the Emancipation Proclamation is:
c. It freed the slaves of any state in open rebellion against the Union, based on military necessity.
Its issuance was not at the end of the Civil War, hence option C is incorrect. It had a considerable impact on the status of enslaved people by shifting the war goals towards ending slavery, contradicting option D. Option A is incorrect as it did not immediately free all enslaved individuals, and option B is partially correct but incomplete as it omits the fact that the Proclamation also did not free slaves in areas already under Union control.