Your comment inspired me to do a bit of research. I'm not sure what these numbers mean, but maybe someone can make heads or tails of them.
1938 Minimum wage: $0.25 (First Minimum Wage Law Enacted)
Adjusted for inflation (2015): $4.14
1940 Minimum Wage: $0.30
Adjusted for inflation (2015): $5.01
1941 Minimum Wage: $0.30 (End of Great Depression)
Adjusted for inflation (2015): $4.77
1945 Minimum wage: $0.40
Adjusted for inflation (2015): $5.19
1950 Minimum wage: $0.75
Adjusted for inflation (2015): $7.27
1955 Minimum wage: $0.75
Adjusted for inflation (2015): $6.54
1960 Minimum wage: $1.00
Adjusted for inflation (2015): $7.90
1965 Minimum wage: $1.25
Adjusted for inflation (2015): $9.27
1970 Minimum wage: $1.60
Adjusted for inflation (2015): $9.64
1975 Minimum wage: $2.10
Adjusted for inflation (2015): $9.12
1980 Minimum wage: $3.10
Adjusted for inflation (2015): $8.79
1985 Minimum wage: $3.35
Adjusted for inflation (2015): $7.28
1990 Minimum wage: $3.80
Adjusted for inflation (2015): $6.79
1995 Minimum wage: $4.75
Adjusted for inflation (2015): $7.28
2000 Minimum wage: $5.15
Adjusted for inflation (2015): $6.99
2005 Minimum wage: $5.15
Adjusted for inflation (2015): $6.16
2007 Minimum wage: $5.85 (Start of Great Recession)
Adjusted for inflation (2015): $6.59
2008 Minimum Wage: $6.55
Adjusted for inflation: $7.11
2009 Minimum Wage: $7.25 (End of Great Recession)
Adjusted for inflation: $7.90
2010 Minimum wage: $7.25
Adjusted for inflation (2015): $7.77
2011 Minimum wage: $7.25
Adjusted for inflation (2015): $7.53
2012 Minimum wage: $7.25
Adjusted for inflation (2015): $7.38
2013 Minimum wage: $7.25
Adjusted for inflation (2015): $7.27
2014 Minimum Wage: $7.25
Adjusted for inflation (2015): $7.16