Coffee first came to North America through New Orleans back in the mid-1700's. It was the time when French brought coffee with as they began to settle new colonies along the Mississippi.
The uniqueness of coffee served in New Orleans is "The taste of coffee and chicory" -- it was developed by the French during their civil war which they imported coffee by mixing it with ground, roasted chicory root (which they could grow locally). It is added to the coffee to soften the bitter edge of the dark roasted coffee.
The original cafe in New Orleans must be "Cafe Du Monde" -- where I visited was the original one in French Market, French Quarter. This stand was established in 1862 and is open 24 hours.
Must try items at Cafe Du Monde are : Coffee (of course) and Beignets.
The recommended coffee of Cafe Du Monde are Black Coffee or Cafe Au Lait (which -- is black coffee mixed half and half with hot milk).
Beignets are square French -style doughnuts, covered with powdered sugar (icing sugar). The texture of beignets is like a Chinese "Youtiao or You Tiao" or "Pah-tong-kho" in Thai -- which is a long, golden-brown, deep fried strip of dough. However, Beignets have more of butter aroma.
To know more about coffee culture in New Orleans : http://www.frenchquarter.com/dining/CoffeeCulture.php
About Cafe du Monde : http://www.cafedumonde.com/main.html