This is not all the historical perspective that I would like. I would love to get some periodic estimates of the wage distribution. What percentage earned the minimum? How many jobs bunched up at the minimum? How did that vary across industries? There is a lot that you could do.
But in lieu of that, I will just give here the real California minimum wage from its beginning in 1918 to the final phase-in of the new plan to raise it to $15 nominal by 2022. (See the text of the bill here.) All numbers are in 2015 dollars. The wage is deflated by the California CPI back until 1956, and the U.S. CPI before that.
An explanation is in order for the projections. Note how the real minimum wage blips downwards in 2023 before stabilizing? That’s because the law has scheduled the wage to reach $15 nominal in January 2022 for large employers (barring a recession) but doesn’t start automatic inflation adjustments until August 2023. (See 1182.2, subdivision (c).)
I will admit to being very surprised that the minimum wage was that high in the 1920s and 1930s.