A 1.7-square-mile city sits entirely inside Oakland because of a rushed 1907 incorporation vote. A campaign to 'cancel' it has revived the question of what that line is actually doing — and the data says: less than you'd think.

Trace a finger around Piedmont on a map and you never leave Oakland. It's a doughnut hole — roughly 1.7 square miles, ringed on every side by a city seventy times its size — and the line dividing the two was set, in part, by people working against a clock.

What put that line back in circulation this week was a rerun. KQED's The Bay pulled up (external source, opens in a new tab) a 2019 Bay Curious history episode about the little city and reposted it. What made the rerun land is newer: for more than a year, an Oakland transit planner named Jesse Rosemoore has been handing out stickers and selling $10 T-shirts that read "CANCEL PIEDMONT" — a jab at the wealth gap that runs along that border.

The border itself predates all of it. In January 1907, as Oakland's council moved to swallow the district, a faction of Piedmont residents petitioned to incorporate instead, and carried the two-thirds vote by a margin of two, according to the city's own founding record (external source, opens in a new tab). Nobody had time to survey a boundary, so they lifted the lines of the existing Piedmont Sanitary District wholesale. By the Historical Society's account, the seam that produced still runs through more than 100 homes and a church — structures that stand in two cities at once.

Today the divide is mostly about money. Census figures put Piedmont at about 67% white and roughly 1% Black; the median home sells near $2.6 million, several times Oakland's, per the reporting that set off the campaign. Inside a city it declined to join, Piedmont runs its own police force and its own schools.

The more useful question is what dissolving the line would change. Oakland Report worked the numbers (external source, opens in a new tab) and found the answer is: not much. Folding Piedmont into Oakland would move the larger city's demographics by under a percentage point, pad its housing stock by 2.2%, and lift its tax revenue by 2.8%. The same analysis points out that Oakland's own council districts split from one another nearly as sharply as Piedmont splits from Oakland — District 1 in the north is about 51% white, District 7 in the deep east about 8%. Piedmont's border is the one you can point to. It isn't the only one on the map.

Walk that edge tomorrow and there's nothing to see — no gate, no marker, just a block where the streetlights and the patrol cars swap jurisdictions, and, in a handful of houses, a property line running clean through somebody's front room.