APPIA, VIA, a high-road leading from Rome to Campania and lower Italy, constructed in 312 B.C. by the censor Appius Claudius Caecus. It originally ran only as far as Capua, but was successively prolonged to Beneventum, Venusia, Tarentum and Brundusium, though at what dates is unknown. Probably it was extended as far as Beneventum not long after the colonization of this town in 268 B.C., and it seems to have reached Venusia before 190 B.C. Horace, in the journey to Brundusium described in Sat. i. 5, followed the Via Appia as far as Beneventum, but not beyond.
The original road was no doubt only gravelled (glarea strata); in 298 B.C. a footpath was laid saxo quadrato from the Porta Capena, by which it left Rome, to the temple of Mars, about 1 m. from the gate. Three years later, however, the whole road was paved with silex from the temple to Bovillae, and in 191 B.C. the first mile from the gate to the temple was similarly treated. The distance from Rome to Capua was 132 m. For the first few miles the road is flanked by an uninterrupted series of tombs and other buildings (see L. Canina, Via Appia, Rome, 1853). As far as Terracina it ran in an almost entirely straight line, even through the Alban Hills, where the gradients are steep. A remarkably fine embankment belonging to it still exists at Aricia. At Forum Appii it entered the Pomptine Marshes; that this portion (19 m. long, hence called Decennovium) belonged to the original road was proved by the discovery at Ad Medias (Mesa) of a milestone of about 250 B.C. (Ch. Hülsen, in Römische Mitteilungen, 1889, 83; 1895, 301). A still older road ran along the foot of the Volscian mountains past Cora, Norba and Setia; this served as the post road until the end of the 18th century. At the time of Strabo and Horace, however, it was the practice to travel by canal from Forum Appii to Lucus Feroniae; to Nerva and Trajan were due the paving of the road and the repair of the bridges along this section. Theodoric in A.D. 486 ordered the execution of similar repairs, the success of which is recorded in inscriptions, but in the middle ages it was abandoned and impassable, and was only renewed by Pius VI. The older road crossed the back of the promontory at the foot of which Terracina stands; in imperial times, probably, the rock was cut away perpendicularly for a height of 120 ft. to allow the road to pass. Beyond Fundi it passed through the mountains to Formiae, the engineering of the road being noteworthy; and thence by Minturnae and Sinuessa (towns of the Aurunci which had been conquered in 314 B.C.)  to Capua. The remains of the road in this first portion are particularly striking.
Between Capua and Beneventum, a distance of 32 m., the road passed near the defile of Caudium (see Caudine Forks). The modern highroad follows the ancient line, and remains of the latter, with the exception of three well-preserved bridges, which still serve for the modern highroad, are conspicuous by their absence. The portion of the road from Rome to Beneventum is described by Sir R. Colt Hoare, Classical Tour through Italy, 57 seq. (London, 1819). He was accompanied on his journey, made in 1789, by the artist Carlo Labruzzi, who executed a series of 226 drawings, the greater part of which have not been published; they are described by T. Ashby in Mélanges de l'Ecole Française de Rome (1903), p. 375 seq., and Atti del Congresso Internazionale per le Scienze Storiche, vol. v. (Rome, 1904), p. 125 seq.
From Beneventum to Brundusium by the Via Appia, through Venusia and Tarentum, was 202 m. A shorter route, but more fitted for mule traffic, though Horace drove along part of it,  ran by Aequum Tuticum, Aecae, Herdoniae, Canusium, Barium, and Gnatia (Strabo vi. 282); it was made into a main road by Trajan, and took the name Via Traiana. The original road, too, adopted in imperial times a more devious but easier route by Aeclanum instead of by Trevicum. This was restored by Hadrian for the 15 m. between Beneventum and Aeclanum. Under Diocletian and Maximian a road (the Via Herculia) was constructed from Aequum Tuticum to Pons Aufidi near Venusia, where it crossed the Via Appia and went on into Lucania, passing through Potentia and Grumentum, and joining the Via Popilia near Nerulum. Though it must have lost much of its importance through the construction of the Via Traiana, the last portion from Tarentum to Brundusium was restored by Constantine about A.D. 315.
The Via Appia was the most famous of Roman roads; Statius, Silvae, ii. 2. 12, calls it longarum regina viarum. It was administered under the empire by a curator of praetorian rank, as were the other important roads of Italy. A large number of milestones and other inscriptions relating to its repair at various times are known. See Ch. Hülsen in Pauly-Wissowa, Realencyclopadie, ii. 238 seq. (Stuttgart, 1896).
 It is important to note how the Romans followed up every victory with a road.
 From Beneventum he followed the older line of the Via Appia to Trevicum; thence, leaving the main road at Aquilonia, he went to Ausculum ("quod versu dicere non est"), the mod. Ascoli Satriano, by a by-road, for the milestones which have been found there, though they probably belong to the Via Traiana, cannot be in their original position, but must have been transplanted thither (Th. Mommsen in Corp. Inscrip. Lat., ix. 1883, No. 6016) - and on to Herdoniae (why Mommsen says that he left Herdoniae on the left, op. cit. p. 592, is not clear), where he joined the line of the later Via Traiana.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)