I got the data from History of minimum wage from DoL and Historical CPU data at the BLS. I used the annual average CPI where available and then just the October 2013 figure for 2013 since they didn't have a 2013 annual average.
Here's the result :
The peak figure was $10.74 in real dollars for 1968. Minimum was just $1.60 in 1968 but in todays dollars thats $10.74. The low was $3.98 in real 2013 dollars from 1944 when the minimum was just 30¢.
I think it would also be pretty meaningful to find out what % of the working population made minimum wage or less but I don't know if I could find that data historically.
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