Adjusted for inflation, the minimum wage's value is sharply down from its peak in 1968, when workers earned the equivalent of $10.15 an hour in 2018 dollars.
The 2019 Raise the Wage Act, introduced by Senator Bernie Sanders and Representative Bobby Scott, would boost wages for nearly 40 percent of all black workers in the United States.
The U.S. army is pursuing recruits in liberal cities, but higher minimum wage laws may be getting in the way.
The lowest paid workers across America will start 2018 with a pay raise thanks to newly enacted minimum wage laws, but advocates say the paychecks are still too low.
The agreement would gradually raise the minimum wage from the current $10 to $15 in 2022.
Demonstrators gathered at 115 locations.