Every state's resident population from 1900 to today (U.S. Census / BEA, via FRED). Switch the view between raw population, people per square mile, and growth since 1950 — the eve of widespread air conditioning and refrigeration. That 1950 line is the preparedness point: places that were nearly empty before you could cool and refrigerate them — Florida, Nevada, Arizona — now hold millions. A high "since 1950" multiple is a grid-down signal: it marks population that the land did not support with pre-modern technology. Pick states on the left to compare, and hover any chart to read the value at that year.
Every state's population from 1900 to today — and how much of it depends on the grid.
Population is a first-order preparedness factor: it drives how much food, water and fuel a place needs, and how hard a prolonged crisis would be. This tool shows the long view — every U.S. state from 1900 on — with one angle you won’t find elsewhere: how much of today’s population only exists because modern climate control made a place livable.
Around 1950, home air conditioning and refrigeration began to spread. They made hot, humid and arid places broadly habitable for the first time. So a state’s growth multiple since 1950 is a grid-down signal:
Florida is the clearest case: about 2.8 million people in 1950 and more than 23 million today — one of the largest states in the country, built on a peninsula that was thinly settled until you could cool and refrigerate it.
This is a context chart, not a forecast. A high multiple doesn’t mean a place is doomed — it means its modern population leans on infrastructure, which is exactly what preparedness planning should account for. Density and growth are computed from the same population series; land area is fixed (U.S. Census).
U.S. Census Bureau / Bureau of Economic Analysis resident population, retrieved via FRED. Annual, 1900–present; refreshed automatically.
