Use of physical force is legally justified only in defense against illegal force, and not as a response to verbal harassment. The legal remedy for verbal harassment is to seek prosecution against the harasser, or to file suit against them. I don't think there are any laws against "dumping somebody's stuff", but destruction of property is a crime and a civil wrong: at any rate, "dumping stuff" (trespass) is not a legally sanctioned response to verbal harassment. Person 2 is thus liable to Person 1 for said "dumping" (though whether that matters depends on whether any loss was suffered). Force may be used to protect property, but your description is of retributive force, not defensive force, and retribution is not an excuse for using force. Thus by attacking Person 2, Person 1 has committed battery. Person 2 may legally use force to stop the battery, thus Person 2 has not committed battery.
In this circumstance, the police will act based on the information they have and believe, so if 1 reports "2 attacked me", they may arrest 2. 2 may protest "it was self defense", and the police have to decide whether to believe that. The ultimate determination of whether 2's force was self-defense is legally determined at trial. Person 2 can attempt to persuade the police or prosecutor that Person 1 is the initial assailant, and may succeed. If they cannot persuade the prosecutor that their version of the story is the truth, they cannot force the prosecutor to go after person 1. In some jurisdictions, there is "private prosecution" where you can hire an attorney to prosecute a person for a crime (thus they must prosecute): it would depend on the state, whether that was an option.