The courteous (and possibly contractually obligated) thing to do is to give your employer your two-weeks notice before leaving your position. You are also usually expected to hand over any company equipment, documents, and anything else they may have given you during your tenure.
Commemoration-wise, there's no national tradition for an employee leaving a company. Some offices will host a party for the employee, thought that is more typical of a retirement than an elected departure. Some employees will elect to bring in donuts for their co-workers, or a cake, or some other gift to the office to thank them for their time together.
But it will vary from state to state, and from town to town, and from company to company. United States businesses are very individualistic, and you'll find each company does things differently - in fact, even offices within the same company will do things a little differently from one another - there really is no standard.
If you want a suggestion, you could mention to your current boss that you'd like to give the office a going-away present to thank them for the many happy hours you worked there, and they might be able to suggest something (baked goods, a new coffee machine, et cetera) but they're just as likely to say 'that's not necessary', and completely mean it. As long as you're responsible in your departure, you've covered all your obligatory bases.