Brief Summary
The Set-Up
African-American voters lived in a world of legal discrimination, despite legal discrimination being outlawed by the Civil Rights Amendments almost a century before.
That clearly needed to change.
The Text
There are a ton of different sections (and some of them are confusing), so here's the lightning round summary of the document.
Deep breaths, here we go:
No region that runs their own voting can restrict based on race or color. If a requirement for voting (like a test, tax, or what have you) seems to be restricting said voting, the Attorney General—who either takes up the case because they've received over twenty complaints from the region or the ratio of white to non-white voters is way off from the ratio of white to non-white citizens—is able to shut down all a state's restrictions to voting until the region proves that they're going to steer straight from now on.
The AG also gets to send in examiners, who serve as their eye on the ground in the region in question. Voters disenfranchised by regional polling practices can go straight to these examiners, and the examiners can override the region's voting laws and put that person straight on a list of eligible voters, which the state will be updated on every month.
States can only get the Attorney General and the examiners out of their hair if they make their case to the U.S. District Court that their voting restrictions will no longer pose a problem to voters of color. In addition, whenever states want to change the laws affecting their voting practices they need to get a thumbs-up from Congress.
Got it? Yeah; it's a lot.
TL;DR
States have to make access to voting equitable, or they'll have some federal houseguests until they do.
And federal houseguests don't just eat all your cereal and use all the hot water. They also make sure your state plays by federal rules.