Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
On the other hand the Latin nationality was, as respected both
the extent of its diffusion and the depth of its hold, in the most
decided ascendant. As after the Social war any portion of Italian
soil might belong to any Italian in full Roman ownership, and any
god of an Italian temple might receive Roman gifts; as in all
Italy, with the exception of the region beyond the Po, the Roman
law thenceforth had exclusive authority, superseding all other
civic and local laws; so the Roman language at that time became
the universal language of business, and soon likewise the universal
language of cultivated intercourse, in the whole peninsula from the
Alps to the Sicilian Straits. But it no longer restricted itself
to these natural limits.
The mass of capital accumulating in
Italy, the riches of its products, the intelligence of its
agriculturists, the versatility of its merchants, found no adequate
scope in the peninsula; these circumstances and the public service
carried the Italians in great numbers to the provinces.(1)