Isn't Federalism fun!
Per the chart in that Wikipedia article, municipalities can ban open carry unless you have a concealed carry licence in Missouri, Nebraska, Oregon, and Philadelphia, Pennsylvania.
The pro-RKBA community is deeply divided on the issue of open carry, and the NRA's cat lady who got the nationwide sweep of concealed carry laws started with Florida in 1986 is I think one of those opposed to it, as well as the usual GOPe types who are as anti-gun as Democrats are, but generally can't be openly so.