Modern America is afflicted with a work problem. Steadily growing numbers of American adults have been dropping out of the workforce, and it seems difficult, if not impossible, to lure many of them back in. While this problem's demographic contours have been examined in some depth, its geographic variability is remarkably under-studied. Today, a stunning 50-plus percentage-point gap separates workforce-participation rates in different metropolitan areas, and between these extremes lies a remarkable national dispersion of local performance that does not fall into predictable regional or economic patterns. This mystery has occasioned strangely little interest, but it demands explanation.