Second Punic War
When the Romans heard that Hannibal was coming, they kept one half of their big army in Italy to fight Hannibal, and they sent the other half of their army to Spain, to take over the silver mines there so the Carthaginians would not be able to pay their soldiers. The general who went to Spain was named Scipio (SKIP-ee-oh).
The war went on for a long time. Hannibal could not conquer Rome, and Rome could not get Hannibal out of Italy. Many thousands of men were killed on both sides. All the elephants died. The Greeks sent some ships to help the Carthaginians.
But finally Scipio succeeded in taking over Spain. Then Scipio took his army to Africa and attacked Carthage itself. The Carthaginian Senate got frightened and told Hannibal to come home and help them. There was a big battle at Zama, near Carthage, in 202 BC, and the Carthaginians lost.
Again the Romans did not take over Carthage itself. But they did take over Spain, and they left Roman soldiers in what is now Morocco and Algeria in North Africa. And they made the Carthaginians agree not to fight any more wars unless the Romans said they could.
To find out more about the Second Punic War, check out these books from Amazon.com or from your library:
The Ancient Roman World, by Ronald Mellor (2004). Straight political history, for middle schoolers.
Classical Rome, by John Clare (1993). For kids, the whole political history from beginning to end.
The Romans: From Village to Empire, by Mary Boatwright, Daniel Gargola, and Richard Talbert (2004). Okay, it's a little dry, but it is up to date and has all the facts you could want.
Hannibal (First Book) by Robert Green (1997). For kids.
The Young Carthaginian by G. A. Henty (1860s, reprinted 2001) This is a good adventure story that can introduce kids to the wars between Rome and Carthage, but because it was written more than 100 years ago, it has some racist and unfair assumptions about the Romans being better people than the Carthaginians - watch out!
Hannibal's War: A Military History of the Second Punic War, by J.F. Lazenby (1978). An academic source.