Tim, the geek, Julie, the popular girl, Rose the quirky one, and Billy the athlete thwarted the Emperors once. But now, the Emperors have a new plan, going back to 1854 to avert the Civil War and set the stage for a future the evil Emperors of Time can control. The four teens must disguise themselves as people who lived in that time to travel back to antebellum Washington DC and hopefully frustrate the Emperors' plans once again.
This is what the Capitol building looked like in 1846. This is the view of the East Side of the Capitol. In 1854, it was under construction but was not completed. Note the dome, which is much different than the modern dome, commissioned in 1855. The Capitol is one of the important settings in Fugitives of Time. You can find out more about the Capitol building at the wikipedia page, which is also where the image to the left came from.
This is a view of Washington DC in 1850. As you can see, it features the Capitol, with other buildings in the background and people bustling around on the road in front of the Capitol and two of the roads leading away behind it. Notice also how green the area nearby looks. In 1850, the nation's capital had a population of 51,687. In comparison, the population in 2014 was 658,893. This picture can be found at this website by Dickinson College. You can find more demographic stats for Washington DC at this page.
This is what the map of the United States looked like in 1854. The dates underneath the names of some of the states or territories show when it became a territory or state. The territory in brown is the most important to the story, since it was the territory that was opened to slavery by the Kansas-Nebraska Act in 1854. Also interesting is the fact that all the continental 48 states are either states or territories by this time. These are the 48 states that make up the entire United States in the Fugitives of Time. You can find other historical maps at this website, which is also where this particular image comes from.