According to independent cartographers I spoke with, the big mapmaking corporations of the world employ type-positioning software, placing their map labels (names of cities, rivers, etc.) according to an algorithm. For example, preferred placement for city labels is generally to the upper right of the dot that indicates location. But if this spot is already occupied—by the label for a river, say, or by a state boundary line—the city label might be shifted over a few millimeters. Sometimes a town might get deleted entirely in favor of a highway shield or a time zone marker. The result is a rough draft of label placement, still in need of human refinement. Post-computer editing decisions are frequently outsourced—sometimes to India, where teams of cheap workers will hunt for obvious errors and messy label overlaps. The overall goal is often a quick and dirty turnaround, with cost and speed trumping excellence and elegance.

By contrast, David Imus worked alone on his map seven days a week for two full years. Nearly 6,000 hours in total. It would be prohibitively expensive just to outsource that much work. But Imus—a 35-year veteran of cartography who’s designed every kind of map for every kind of client—did it all by himself. He used a computer (not a pencil and paper), but absolutely nothing was left to computer-assisted happenstance. Imus spent eons tweaking label positions. Slaving over font types, kerning, letter thicknesses. Scrutinizing levels of blackness. It’s the kind of personal cartographic touch you might only find these days on the hand-illustrated ski-trail maps available at posh mountain resorts.

A few of his more significant design decisions: Your standard wall map will often paint the U.S. states different colors so their shapes are easily grasped. But Imus’ map uses thick lines to indicate state borders and reserves the color for more important purposes—green for denser forestation, yellow for population centers. Instead of hypsometric tinting (darker colors for lower elevations, lighter colors for higher altitudes), Imus uses relief shading for a more natural portrait of U.S. terrain.

The Essential Geography of the United States of America via Slate.