One of my favorite books, Etiquette for Gentlemen, has some excellent tips for the polite American Gentlemen.
When a man marries, all acquaintance with his former companions ceases; and unless it is renewed by sending them the cards of the new-married couple, they are no longer on visiting terms. Reasons of economy may render an extensive connexion imprudent, and sound discretion will immediately suggest that many of the bachelor's most agreeable companions would be very improper connexions for a benedict, and by no means prudent associates of the domestic hearth. Custom has established this rubicon, and has dictated that no offence shall be taken by those who not the passport.
If you wish to dance with a lady at a public ball, the master of ceremonies will introduce you , if there be no difference in station and the lady has no objection.
If there be another chair in the room, do no offer a lady that from which you have just risen.
Gentility is neither in birth, manner, nor fashion, but in the mind. A high sense of honor - a determination never to take mean advantage of another - an adherence to truth, delicacy and politeness towards those with whom you may have dealings - are the essential and distinguishing characteristics of a gentleman.