Walk a block off Canal (away from the quarter on Carondelet Street I think) to avoid the crowd waiting to board at Canal, then ride to the curve in the tracks (Carrollton stop) Hop off, have a nosh at La Madelines, then hop back on and ride back to Canal. Be sure to sit on the same side of the streetcar each way so you can see both sides of the street and enjoy the wonderful homes.
Recommended to take it near dusk - you know when it's still light enough that people leave their drapes open, but have lights on in the house??? Then sometimes you get to see inside!
HEY... from the streetcar, it's OK...
Also for feel of what a plantation home is like visit Longue Vue Gardens
http://www.longuevue.com It's not easy to get to, but it's a nice place to visit