About one hour and 47 minutes according to MapQuest.
Google Maps estimates the driving time as 1 hour and 39 minutes.
That is a fairly short drive depending on where in Milwaukee you live. Worst case is about an hour.
If you were to drive from Austin to Milwaukee it would take about 19 hours and 2 minutes. That is assuming that you are drving to Milwaukee.
It is not possible to drive from Chicago to Hawaii
Check Mapquest.com
... from where..?
I assume you mean Milwaukee, Wisconsin (as opposed to Milwaukee, North Carolina). The distance to New Orleans from Milwaukee is 912 miles. How long that distance would take you to drive depends on how fast your average speed is. Driving an average of 50 MPH, it would take you 18.24 hours.
a long time
20 hours
It will require about 28.5 hours to drive that 1,781 miles.
Goole maps
According to mapquest it takes 22hrs and 34mins to drive from Milwaukee Wisconsin to Naple's Florida.