John D. Rockefeller founded Standard Oil in Cleveland in 1870, and in under four months in 1872 -- an event locally remembered as the "Cleveland Conquest" -- it absorbed 22 of the city's 26 oil refineries, making Cleveland the world's largest oil-refining center for the rest of the 19th century. The city's population reflected it: 381,768 in 1900, 560,663 by 1910, peaking at 914,808 in 1950. Then a 60-year decline erased more than half of it. But two institutions were growing the entire time, not after the collapse. Cleveland Clinic opened February 28, 1921 -- founded by four doctors who had run a cooperative military medical unit in World War I and rebuilt it as civilian practice -- and never stopped. It now runs 23 hospitals and 300 outpatient locations, employs 83,000 people, sees nearly 6 million patient visits a year from all 50 states and more than 100 countries, and Newsweek has ranked it the #2 hospital in the world for five straight years -- #1 in cardiology for twenty. NASA's Aircraft Engine Research Laboratory opened in Cleveland in 1941, built the world's most advanced wind tunnel by 1944, helped cool B-29 engines and test America's first jet engines during the war, then became NASA Lewis Research Center and worked on liquid hydrogen rocket fuel for Mercury and Apollo. And in 1969, while both institutions were already decades into that growth, an oil slick on the Cuyahoga River caught fire for the thirteenth documented time since 1868 -- five stories of flame that made national news and helped force the creation of the EPA and the Clean Water Act. The fire was the visible story. The clinic and the lab were the real one, the whole time.