In many, probably most places, that seems to be the case. New York State is an exception. The law there was changed by the courts and it has been made clear to the police that they are not to stop women from going topless in public. Likewise with the District of Columbia. Some cities have also informed their police that they are not to harass women who go topless. Honolulu, Madison, Santa Fe, Austin, Boulder, Portland and some others all permit women to go topless.
Of course public breastfeeding is protected in every state but Idaho, so women cannot be arrested for that even if the law otherwise prohibits women from going topless. Don't know why Idaho hasn't made it legal--maybe something about their famous potatos.