Gwinnett County · The I-85 corridor
Mulberry History
This page is the history section of the Mulberry guide: how the neighborhoods long known as Hamilton Mill became the city that voted itself into being in 2024, and the older, stranger story of Duncan City, a historic community just over the county line that is not a city at all.
Mulberry became Georgia's newest city in May 2024, when voters on Gwinnett's northeast side approved a new municipality covering the neighborhoods long known as Hamilton Mill and the country roads around them, near where I-85 crosses toward the Hall and Barrow county lines.
Locals still talk in school-district terms, Mill Creek side or Dacula side, because the new city line did not rewrite that map. The area has gone from farmland to new-home neighborhoods in recent decades, keeping horse farms and open land nearby.
The local history that makes the news
The one-man settlement at the county line
Duncan City was never an incorporated city and it is not one now. It never had a city hall, a mayor, an official boundary, or an address you can type into a map. It is a historic community name for one man, one house, and one intersection in the old countryside near the Gwinnett and Hall county lines, kept alive because of what that man did with a road sign.
Read this first
Duncan City is a historic community, not a current city. It appears on no current map, is governed by no city, and has no offices or services. The name survives for one reason: the sign Lucius Duncan built, and the 1979 television report that told the country about it.
Lucius Duncan was 78 years old and the lone resident of his own self-styled city. He had spent 65 years giving lost motorists directions, usually at the cost of the dinner cooling on his table. He asked the county to put up road signs at his four-way crossing, and the county declined.
So he built the road sign himself, a stop-sign style board with a written message for lost drivers and arrows for the ones who kept asking anyway. Locals knew the corner as Duncan's Corner, and the sign turned it into a landmark.
The story went national in 1979 in a CBS Evening News segment with Walter Cronkite. A network crew came out to a one-house crossing, met its 78-year-old resident, and gave the sign a permanent place in the telling of this corner of Georgia.
CBS Evening News with Walter Cronkite, 1979: the report on Lucius Duncan of Duncan City. Watch on YouTube
History stays history; the working guides cover what is open and worth knowing today. If you are weighing a move around Mulberry, book a call with Rob Dietrich, the REALTOR® behind this guide.
An editorial guide, not a listings site. Updated September 9, 2026. Real-estate guidance on this page is provided by Rob Dietrich, REALTOR with eXp Realty, LLC.