In the case of the plat map, an abstract is actually literal.

These old sheets laid out the legal names for the streets and real estate parcels, creating a visual database of the city. They were bound in thick, important-looking volumes, printed on heavy paper that feels like a stiff bedsheet. With their simple color code — pink for brick, yellow for wood, brown for stone — and tiny hand-drawn letters that look like the calligraphy of elegant ants, they are excruciatingly detailed.

They’re also pieces of conceptual art.

If you wish, you can read them as a disquisition on capitalism’s ability to commodify the terrain, turn the broad open land into slices of private property with a monetary value. You can peer at a tiny line and imagine a story of two neighbors arguing over a fence, or see a block crammed with the names of businesses and imagine a Balzac novel overflowing with commerce and conflict.

Plat maps remind you that everything passes — the buildings rise and fall, the names of the owners and developers bloom and fade. But the arteries and capillaries of the streets are constant.

Plat maps are also quite lovely and if they’re old enough, quite rare.

Plat maps from 1914. The maps mainly consist of three colors: pink for brick buildings, yellow for wood buildings and brown for stone buildings.

“I would love to know how many copies were made,” says Althea Willette, plat map collector and dealer at Missouri Mouse Antiques in St. Paul. “I’d say less than 50.”

But that’s per edition. As the city grew, new maps were required, and there were many editions, known by the names of their publishers.

“The first real estate maps in Minneapolis were in 1885,” said Willette. “The Donelley Co. did a wonderful two-volume set in 1892. Then there’s 1903, 1914 and 1940. The 1940 one has a tremendous loss of detail. It [detail] exists, but it’s nothing to write home about. In St. Paul, the first [plat map] was done in 1884; there’s an 1887 one that’s not very nice, and 1908, that’s the D.L. Curtis edition. It’s not hand-colored.”

Others were tinted by hand? “Yes! The coloring was done by women and children, according to anecdotes.”

Lettered by hand, as well, with fonts invented by the artist. It’s one of those details that draws collectors like Willette to pore over old plat maps. “There’s always some interesting little remnant detail,” she says.

Indeed. If you examine the maps with a magnifying glass, the colored blocks and numbers turn into something else: a historical snapshot of a bygone city.

According to the 1894 maps, for example: The wasteland north of Hennepin (the North Loop, as it’s called now) was once bustling with houses and commercial buildings. The map calls it the Wilson, Bell and Wagner’s Addition, so if the area ever gets hip and hot they could call it WilBelWag.

The great trough of Interstate 94 and the widening of Hwy. 55 made the area unrecognizable today. Some streets have new names (Western is now Glendale) while others, like Lakeside Avenue, have vanished entirely — along with one of the city’s most fashionable neighborhoods.

A current map shows the farmers market, warehouses, parking lots. The old plat map shows a tiny residential neighborhood with curving streets and “Oak Lake Park” in the middle, complete with pond. It was a cozy enclave for the rich in the 1880s, but it lost prestige to nearby Loring Park. The creek went foul and the railroad built a sooty coal shed by the roundhouse, and that was it for Oak Lake Park. Gone and forgotten, but it still looks charming on the map.

Sometimes forgotten citizens can be found on the tinted grid, demanding your attention.

Plate 55 concerns the Lynnhurst neighborhood, in southwest Minneapolis. The map could be used to find your way around today; nothing has changed. But there’s one big plot of land on the corner of Lyndale and Minnehaha Parkway, which is marked NELLIE FITCHETTE.

The City Council minutes from 1898 contain a note about Nellie, who objected to a payment of $600 for widening the parkway and thus eating into her property. She settled for $500, provided the city paid her immediately, put in sod to cover the damage, and exempted her from assessment due to area improvements.

She was a tough nut, Nellie. There ought to be a statue.

What we don’t know

Run your finger along Plate 32, tracing the gash that I-35W would make in a few decades, and you find some buildings — and ideas — no longer around. There was Thomas Arnold’s School for Boys, a home for “delinquents, retarded and dissatisfied boys.”

Later renamed, it was described in a Minneapolis Public School history as a “ ‘fresh-air school’ where students who had ‘tubercular tendencies’ studied in the dead of winter in classrooms with wide-open windows.” How that cured dissatisfaction one can only guess.

Those are just a few observations from a few inches from a few maps with fairly few details. Willette has some maps that show all the business names downtown in the 1920s. Each little annotation — Uhgers Lunch, Marienhoff Tailor, Stove Repair — is a story we’ll never know.

Who was the cook at Uhger’s? Did Mr. Marienhoff wince when he knelt down to measure trousers because he wrecked his back in World War I? What was life like for a stove repairman, going from house to house to fix the burners?

In a way, the maps are as frustrating as they are tantalizing, because they hint at so much that we just can’t know. But we know there was a Nicollet Avenue, and while it’s different today, it’s still Nicollet. The cast of characters change, but they have the same ancestors.

Plat maps are our family tree.