Of the actual state of the Roman commerce about this time we know very little, but that it was lucrative, may fairly be inferred from the following circumstance:--A little before the commencement of the second Punic war, Caius Flaminnus was extremely desirous to obtain the support and good will of the populace; with this object in view, he joined the tribunes of the people in passing a law, which is called the Flaminian, or Claudian law. By it, the senators, who had been accustomed to acquire considerable wealth by fitting out ships and trading, were expressly forbidden to possess or hire any vessel above the burden of 300 amphorae or eight tons, and not more than one vessel even of that small tonnage. This vessel was allowed them, and was deemed sufficient to bring the produce of their farms to Rome. By the same law, the scribes, and the clerks, and attendants of the quæstors, were prohibited from trading; and thus the liberty of commerce was exclusively confined to the plebeians.

Whilst Hannibal threatened the Romans in the vicinity of Rome itself, they had neither leisure, inclination, or means, to cope with the Carthaginians by sea; at length, however, Marcellus, having checked the enemy in Italy, maritime affairs were again attended to. Scipio, who had been successful in Spain, resolved to attempt the reduction of New Carthage: this place was situated, like Old Carthage, on a peninsula betwixt a port and a lake: its harbour was extremely commodious, and large enough to receive and shelter any fleet. As it was the capital of the Carthaginian dominions in Spain, here were deposited all their naval stores, machines used in war, besides immense treasures. It was on this account extremely well fortified, and to attempt to take it by a regular siege seemed to Scipio impracticable: he, therefore, formed a plan to take it by surprise, and this plan he communicated to C. Lælius, the commander of the fleet, who was his intimate friend. The Roman fleet was to block up the port by sea, while Scipio was to blockade it by land. The ignorance of the Romans with regard to one of the most common and natural phenomena of the sea, is strongly marked in the course of this enterprise. Scipio knew that when the tide ebbed, the port of New Carthage would become dry and accessible by land; but his soldiers, and even his officers, were ignorant of the nature of the tides, and they firmly believed that Neptune had wrought a miracle in their favour, when, according to Scipio's prediction, the tide retired, and the army was thus enabled to capture the town, the walls of which on that side were extremely low, the Carthaginians having directed all their attention and efforts to the opposite side. The capture of New Carthage depressed, in a great degree, the spirits, as well as weakened the strength of the Carthaginians in Spain: eighteen galleys were captured in the port, besides 113 vessels laden with naval stares; 40,000 bushels of wheat, 260,000 bushels of barley, a large number of warlike machines of all descriptions, 260 cups of gold, most of which weighed a pound, 18,300 pounds weight of silver, principally coin, besides brass money, were among the spoils.

About the year of Rome 556, Scipio had succeeded in reducing all Spain. It does not appear, however, that the Romans were thus enabled greatly to extend their commerce; indeed, at this period, we have no evidence that any other town in Spain, except Gades, possessed any considerable trade. This island and city were situated in a gulph of the same name, between the straits of Gibraltar and the river Boetis; and, from the remotest period of which we possess any records, was resorted to by foreigners for the purposes of commerce. Gradually, however, the inhabitants of Spain, under the Roman government, enriched themselves and their conquerors by their industry: large quantities of corn, wine, and oil were exported, besides wax, honey, pitch, vermilion, and wool. The oil and wool were deemed equal, if not superior, to those of any other part of the world: the excellent quality of the wool is a strong fact, against an opinion entertained by many, that the fineness of the Spanish was originally derived from the exportation of some English sheep to Spain, since it appears to have been celebrated even in the time of the Romans: how important and lucrative an object it was considered, may be collected from the attention that was paid to the breed of sheep; a ram, according to Strabo, having been sold for a talent, or nearly 200 l. Horace incidentally gives evidence of the commercial wealth of Spain in his time, when he considers the master of a Spanish trading vessel and a person of great wealth as synonimous terms.

As Hannibal still continued in Italy, the senate of Rome resolved to send Scipio into Italy, with a discretionary power to invade Africa from that island. He lost no time in equipping a fleet for these purposes, and his efforts were so well seconded by the zeal and activity of the provinces and cities, many of which taxed themselves to supply iron, timber, cloth for sails, corn, &c. that, in forty days after the timber was felled, Scipio had a fleet of thirty new galleys.

Soon after he landed in Sicily, he resolved to invade Africa: for this purpose his fleet was collected in the port of Lilibæum. Never was embarkation made with more order and solemnity: the concourse of people who came from all parts to see him set sail, and wish him a prosperous voyage, was prodigious. Just before he weighed anchor, he appeared on the poop of his galley, and, after an herald had proclaimed silence, addressed a solemn prayer to the gods. It is foreign to our purpose to give any account of the campaign in Africa, which, it is well known, terminated in the utter defeat of the Carthaginians, who were obliged to sue for peace. This was granted them on very severe terms: all the cities and provinces which they possessed in Africa previously to the war, they were indeed permitted to retain, but they were stripped of Spain, and of all the islands in the Mediterranean; all their ships of war, except ten galleys, were to be delivered up to the Romans; and, for the future, they were not to maintain above that number at one time: even the size of their fishing boats and of their trading vessels was regulated. In the course of fifty years ten thousand talents were to be paid to the Romans. During a short truce which preceded the peace, the Carthaginians had seized and plundered a Roman squadron, which had been dispersed by a storm, and driven near Carthage; as a satisfaction for this, they were obliged to pay the Romans 25,000 pounds weight of silver. The successful termination of the second Punic war gave to the Romans complete dominion of the sea, on which they maintained generally 100 galleys. Commerce flourished, particularly that most important branch, the trade in corn, with which Rome, at this period, is said to have been so plentifully furnished, that the merchants paid their seamen with it.

The power of the Romans at sea was now so well established, that no foreign power could hope to attack, or resist them, unless they were expert navigators, as well as furnished with a numerous fleet. Under this impression, Philip king of Macedon, who had long been jealous and afraid of them, applied himself sedulously to maritime affairs. As it was about this period that the Romans began to turn their thoughts to the conquest of Greece, it may be proper to take a retrospective view of the maritime affairs and commerce of that country. An inspection of the map of Greece will point out the advantages which it possessed for navigation and commerce. Lying nearly in the middle of the Mediterranean, with the sea washing three of its sides; possessed of almost innumerable inlets and bays, it was admirably adapted to ancient commerce. Its want of large and navigable rivers, which will always limit its commerce in modern times, presented no obstacle to the small vessels in which the ancients carried on their trade; as they never navigated them during the winter, and from their smallness and lightness, they could easily drag them on shore.

Athens, the most celebrated state in Greece for philosophy, literature, and arms, was also the most celebrated for commerce. The whole of the southern angle of Attica consisted of a district called Parali, or the division adjacent to the sea. In the other districts of Attica, the soldiers of the republic were found: this furnished the sailors; fishing and navigation were the chief employments of its inhabitants. About 46 miles distant from the Piraeus, stood Sunium, the most considerable town in this district: it possessed a double harbour in the Mediterranean.

The principal commerce of Attica, however, was carried on at Athens: this city had three harbours: the most ancient was that of Phalerum, distant from the city, according to some authors, 35 stadia; according to others only 20 stadia. It was nearer Athens than the other two, but smaller, and less commodious. Munichea was the name of the second harbour: it was formed in a promontory not far distant from the Pirasus, a little to the east of Athens, and naturally a place of great strength; it was afterwards, at the instance of Thrasybulus, rendered still stronger by art. But by far the most celebrated harbour of Athens was the Piraeus. The republic of Athens, in order to concentrate its military and mercantile fleets in this harbour, abandoned that of Phalerum, and bent all their efforts to render the Piraeus as strong and commodious as possible. This occurred in the time of Themistocles; by whose advice both the town and the harbour were inclosed with a wall, about seven miles and a half long, and sixty feet high. Themistocles' intention was to have made it eighty cubits high, but in this he was opposed. Before this connecting wall was built, the Piraeus was about three miles distant from the city. As the strength of the wall was of the utmost importance, it was built of immense square stones, which were fastened together with iron or leaden cramps. It was so broad that two waggons could have been driven along it. The Pireus contained three docks; the first called Cantharus, the second Aphrodisium, and the third Zea. There were likewise five porticos, and two forums. The Piraeus was so celebrated for its commerce, that it became a proverbial saying in Greece, "Famine does not come from the Piræus." The extent and convenience of the Piræus may be judged of from this circumstance, that under the demagogue Lycurgus, the whole naval force of the nation, amounting to 400 triremes, were safely and easily laid up in its three harbours.

Before the time of Themistocles, Athens does not appear to have devoted her attention or resources to maritime affairs: but this celebrated general not only rendered the Piræus stronger and more commodious, but also procured a decree, which enabled him to add twenty ships to the fleet annually. The sums arising from the sale of the privileges of working the mines, or the eventual profits of the mines, which had formerly been distributed among the people, were, through his influence, set apart for the building of ships. Afterwards a law was passed, which taxed all the citizens who possessed land, manufactories, or money in trade or with their bankers; these classes of the citizens were also obliged to keep up, and increase, if occasion required it, the naval force of the republic. When it was necessary to fit out an armament, as many talents as there were galleys to be built and equipped, were raised in each of the ten tribes of Athens. The money thus collected was given to the captains of the galleys, to be expended in the maintenance of the crew. The republic furnished the rigging and sailors: two captains were appointed to each galley, who served six months each.

Although the vessels employed by the Athenians both for war and commerce were small compared with those of modern days, and their merchant ships even much smaller than those of the Phoenicians, if we may judge by the description given by Xenophon of a Phoenician merchant vessel in the Piræus, yet the expence attending their equipment was very great. We learn from Demosthenes, that the light vessels could not be kept in commission, even if the utmost attention was paid to economy, and no extraordinary damage befel them, for a smaller sum than about 8000 l. annually; of course, such vessels as from their size, strength, and manning, were capable of standing the brunt of an engagement, must have cost more than double that sum.