In 1919, a Black teenager drowned in Lake Michigan after crossing an invisible segregation line, and the riot that followed killed 38 people. In 1962, the city made that same line physical -- rerouting the Dan Ryan Expressway around a White neighborhood instead of through it, still measurable today as a 30-year life-expectancy gap between two Chicago neighborhoods nine miles apart.

The world's largest futures exchange by volume traces back to farmers dumping grain into Lake Michigan in the 1840s because storing it cost more than it was worth. Chicago merchants organized the Board of Trade in 1848 to fix that -- the direct ancestor of the $11.6 billion 2007 merger that created CME Group.

The world's largest known gold depository isn't Fort Knox -- it's 80 feet below a Lower Manhattan street, holding roughly 500,000 bars worth close to $200 billion, none of it owned by the Fed itself. The same block spent two and a half months as a closed emergency perimeter after 9/11.

In the 1790s, New York was only the seventh-largest US port. By 1830 it was the largest, and never lost that position -- not because the harbor changed, but because the state dug the Erie Canal, cutting shipping costs from Buffalo to New York from $90 a ton to $4.

New York City came within days of bankruptcy in 1975, and the state took real control of its budget -- but got it back within a decade. Washington, DC never had that starting point to return to: Congress has retained permanent authority over its budget since 1973, crisis or not.

Second Baptist Church, founded in 1836 by 13 formerly enslaved people, ran an Underground Railroad station in its own basement for nearly 30 years, helping as many as 5,000 people cross into Canada. The Lions became the first NFL team to finish 0-16, and fans stayed fifteen more years anyway -- the same civic instinct running through three different centuries.

In 1956, Pittsburgh's urban renewal authority demolished the Lower Hill District to build a Civic Arena, displacing 8,000 residents. Fifty-two years later, when the Penguins needed a new arena on nearly the same ground, the Hill District wasn't cleared again -- almost 100 community groups negotiated binding veto power over the neighborhood's own master plan first.

Between 25,000 and 35,000 low-income American high schoolers score in the top 10% nationally, but only 34% of the highest scorers from the bottom income quartile end up at a selective college -- even though a selective college's more generous financial aid would often cost them less than the school they actually enroll in instead.

Route 128, completed in 1956, was the nation's first real high-tech corridor -- built on defense money five years before Silicon Valley. By the 1980s it should have been Silicon Valley; a 1994 study found Silicon Valley's open networks simply out-adapted Route 128's closed corporations.

The garage-startup story leaves out the tenant that mattered most: by 1959, Lockheed Missiles and Space Company employed nearly 20,000 people in Palo Alto and Sunnyvale building nuclear missiles, and was Santa Clara County's largest employer for decades before personal computers ever took over.

Phylloxera wiped out 85% of Napa's vineyards by 1900. The fix was grafting French vines onto resistant American rootstock, and growers still rebuild the soil every year since. Eighty-six years later, Napa wines beat France's own best in a blind Paris tasting.

The film industry fled to Los Angeles to escape Thomas Edison's East Coast patent monopoly on movie cameras. A decade later, Donald Douglas founded Douglas Aircraft in 1921 by literally renting space in an abandoned movie studio, for nearly identical reasons.