CONFIRMEDDate confidence: CONFIRMEDStated as firmHow firmly the source words the date: confirmed, scheduled, estimated, delayed or unverified.Show all CONFIRMED pins84% CONFIDENCEOverall confidence: 84%How well the pin's source and references back up its dates.Weighted average of how firmly 4 references, the source included, support the pin's start and end times; a reference counts half as much for every 180 days older than the newestShow all pins at 75% confidence or better
Happened as dated, per the source[1]: "President Franklin D. Roosevelt dedicates dam September 30th."President Franklin D. Roosevelt dedicated the Hoover Dam on the Colorado River, then the largest concrete structure ever built.
$49M
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