Here's a Mapquest map showing the (approximate) route of the long-since-filled New Basin Canal, built by immigrant labor (mostly Irish) in the 1830s. Slaves were considered too valuable to risk in the disease-ridden swamps, so newcomers from Europe were welcome to defy death for a few pennies a day.

Ironically enough, we now know that natives of the area, white and black alike, were immune to Yellow Fever and other such local diseases, and would have survived the same working conditions that killed so many immigrant workers. Nobody understood that then, sadly enough.

Most of the canal's route. once filled in and paved over, became the "Pontchartrain Expressway" from the suburban areas near the lakefront to the Mississippi River Bridge. Most of the expressway eventually became part of the I-10 when the interstate highway system was developed through the late 50s and 1960s.

http://www.mapquest.com/mq/10-irxmiq4n0k7MSytuKd7Z

Note: The actual lakefront in the 1830s was somewhat further "inland" (south) than the current shoreline. The starting point for my Marpquest request for directions, near the corner of Pontchartrain Blvd. and Robert E Lee, may have been offshore in 1830. The downtown end of the canal was a turning basin abutting the curved section of Basin St, but the actual route of the old canal from the current I-10/US-90 right-of-way across the Central Business District to the Treme/Storyville area just north of the French Quarter is no longer clearly visible ~ probably along Loyola Ave., more or less...