From the Document: "Since 2016, voters in eight states approved ballot measures to increase state minimum wage rates. These and previous ballot measures provide states one way of establishing minimum wage provisions different from those required by the Fair Labor Standards Act (FLSA; P.L. 75-718). The FLSA, enacted in 1938, is the federal legislation that establishes the general minimum wage that must be paid to all covered workers. The Department of Labor (DOL) estimates that more than 130 million workers are subject to the provisions of the FLSA. Since the FLSA established a minimum wage of $0.25 per hour in 1938, Congress has amended the act numerous times, typically to expand coverage or raise the wage rate. Since its establishment, the federal minimum wage rate has been raised 22 separate times, most recently in 2007, when it was increased from $5.15 per hour to its current rate of $7.25 per hour in three steps (the final step occurring in 2009). [...] States generally have three options in setting their minimum wage policies 1. they can set their own minimum wage provisions that differ from those in the FLSA, 2. they can explicitly tie their minimum wage provisions to the FLSA, or 3. they can include no specific minimum wage provisions in state law."
CRS Report for Congress, R44706
Congressional Research Service: https://crsreports.congress.gov/