Final answer:
Slaves were informed about the Emancipation Proclamation through the 'grape-vine' telegraph and direct communication when Union officers read the proclamation aloud to them. Information circulated via whispered discussions and exchanges at post offices, and the approach of Union troops often resulted in slaves learning about their emancipation.
Step-by-step explanation:
Slaves during the Civil War era were kept informed about the Emancipation Proclamation and other significant national events despite their limited access to books or newspapers. This information was shared through the "grape-vine" telegraph, which consisted of overheard conversations and information passed along by individuals. Slaves would learn about the outcomes of battles and the progress of the Union army from sources such as the colored man sent to retrieve mail from the post office. Furthermore, the presence of Union troops in the South as the war progressed also played a crucial role in spreading the news of emancipation.
When the Emancipation Proclamation took effect, it signaled the beginning of the end for slavery and led to nearly 200,000 black soldiers joining the Union forces, which significantly impacted the course of the war. However, the actual communication of emancipation to the slaves often occurred through direct readings of the proclamation by individuals such as United States officers to an assembled group of slaves.