The unearthed site includes the remains of a water-powered flour mill used to grind grain and produce food for the soldiers, clothes, food remains, graves and pottery.
It also contains evidence the Roman occupants might have worn socks, experts who analysed ancient sandals said.
The site was excavated as part of a £318 million Highways Agency scheme to upgrade the A1 between Dishforth and Leeming in North Yorkshire.
It is close to a ruined fort at Healam Bridge, which formed part of the Roman frontier 2,000 years ago.
It is thought the military outpost was used by the Roman Ninth Hispanic Legion, which disappeared some time in the 2nd Century AD.
Cultural heritage team leader Blaise Vyner said: “We know a lot about Roman forts, which have been extensively studied, but to excavate an industrial area with a mill is really exciting.