"What if Abraham Lincoln never freed the slaves?" That's the question Mr. Caruthers poses to his third grade history class. And the question takes on real-life importance for Abigail, Zack, Jacob, and Bo, because Mr. Caruthers wants them to travel back in time and convince President Lincoln to write the Emancipation Proclamation. Lincoln is discouraged and thinking of quitting--before slavery is abolished!

With a time-travel gadget and only two hours to spare, Abigail and her friends are going back to the past. But even though time travel isn't hard, convincing Abraham Lincoln not to give up isn't going to be easy...