When adjusted for inflation, the federal minimum wage in the United States has fallen to levels not seen since 1949. The current federal minimum wage of $7.25 per hour has the lowest purchasing power since then. This decline is due to the fact that the federal minimum wage has not been raised since 2009, while inflation has continued to erode its value.
Sources:
https://www.statista.com/statistics/1065466/real-nominal-value-minimum-wage-us/