What is the best visual aid if a presenter wants to show the audience the location of an important Civil War battle?

Any speaker addressing an audience about the US Civil War and its battles can use two sources to present to the audience. One is a typical road atlas for each state that shows people what the state of, as example, Pennsylvania looks like now, and also retrieve for the internet a good map of the battlefield of say, Gettysburg, where that 3 day battle took place. In that way it can be seen how complex Pennsylvania is now and how much "less complex" that state and Gettysburg was back in 1863.