All that Sicily lost through Roman domination Africa gained. It gradually replaced Sicily as an unwilling granary for Rome; but in return Roman soldiers, colonists, businessmen, and engineers made it blossom into a hardly credible affluence. Doubtless the new conquerors had found certain regions thriving when they came; between the mountains that frowned upon the Mediterranean, and the Atlas range that kept out the Sahara, ran a semitropical valley sufficiently watered by the Bagradas (Medjerda) River, and two months of rain, to repay the patient husbandry that Mago had taught and Masinissa had enforced. But Rome improved and expanded what she found. Her engineers built dams across the rivers that flowed down from the southern hills; they gathered the surplus water in reservoirs in the rainy season, and poured it into irrigation canals in the hot months when the streams ran dry. Rome asked no heavier taxes than native chiefs had levied, but her legion and fortifications gave better protection against nomad raiders from the mountains; mile by mile new soil was won from desert or savagery for cultivation and settlement.
The valley produced so much olive oil that when in our seventh century the Arabs came, they were amazed to find that they could ride from Tripoli to Tangier without ever moving from the shade of olive trees. Towns and cities multiplied, architecture exalted them, and literature found new voice. The ruins of Roman forums, temples, aqueducts, and theaters on now arid wastes reveal the reach and wealth of Roman Africa. Those fields decayed and became dead sand not through a change in climate but through a change in government- from a state that gave economic security, order, and discipline to one that allowed chaos and negligence to ruin the roads, reservoirs, and canals. At the head of this restored prosperity was the resurrected city of Carthage.
After the battle of Actium Augustus took up the frustrated project of Caius Gracchus and Caesar and sent to Carthage as colonists some of the soldiers whose fidelity and victories he wished to reward with land. The geographical advantages of the site, the perfect harbor, the fertile Bagradas delta, the excellent roads opened or reopened by Roman engineers, soon enabled Carthage to recapture from Utica the export and import trade of the region; within a century of its refounding it had become the largest city in the western provinces.
Rich merchants and landowners built mansions on the historic Byrsa, or villas in the flowering suburbs, while peasants driven from the soil by the competition of latifundia joined proletaires and slaves in slums whose fetid poverty would welcome the egalitarian gospel of Christianity. Houses rose to six or seven stories, public buildings gleamed with marble, and statuary of good Greek style abounded in the streets and squares. Temples were built again to the old Carthaginian gods, and Melkart enjoyed till our second century the sacrifice of living children. The people rivaled the Romans in their passion for luxuries, cosmetics, jewelry, dyed hair, chariot races, and gladiatorial games.