After the Civil War, why would electing African American representatives to Congress be important to achieving freedom for people recently freed from slavery?

As the Union armies advanced through the Confederacy, thousands of slaves were freed each day until nearly all (approximately 3.9 million, according to the 1860 Census) were freed by July 1865. While the Proclamation had freed most slaves as a war measure, it had not made slavery illegal.

Explanation:

“i think it is very plausible that if there are five votes to end the death penalty, it could be with the people who are on the court right now,” - smith

so basically it is not clearly and consistently imposed