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
Following in the steps of Claudius, the Roman senate wove around Italy
that network of roads and fortresses, the formation of which has
already been described,(39) and without which, as the history of all
military states from the Achaemenidae down to the creator of the road
over the Simplon shows, no military hegemony can subsist.
Following in
the steps of Claudius, Manius Curius built from the proceeds of the
Pyrrhic spoil a second aqueduct for the capital (482); and some years
previously (464) with the gains of the Sabine war he opened up for the
Velino, at the point above Terni where it falls into the Nera, that
broader channel in which the stream still flows, with a view to drain
the beautiful valley of Rieti and thereby to gain space for a large
burgess settlement along with a modest farm for himself. Such works,
in the eyes of persons of intelligence, threw into the shade the
aimless magnificence of the Greek temples.