Los Angeles and Minneapolis are among the latest. Oddly enough, that's roughly the inflation-adjusted 1968 minimum wage, in the peak year of U.S. dollar buying power. Right wingers trash any government intervention as hurting the sacred free market. That sacred cow is pure bull. There's no such thing as a free market.
Governments intervene all the time.
Corporate propagandists have made official meddling somehow acceptable for soul-less companies, but not for their workers. That's why the eight-hour day and overtime pay are now targeted for extinction in the house Newt built. Witness the sad fate of AB 506, the Displaced Workers Bill of Rights killed by the Nevada assembly a few days ago. Every business entity in the state came out to knife it. Tom and Kathy Stoneburner and a few laid off workers.