I have no idea how Louisiana beat us, but Hawaii is the second happiest state in the Union, according to a recent study published by the UK’s University of Warwick and Hamilton College in the US.

They were looking at the happiness levels of one million US citizens to discover which
are the best and worst states in which to live in the United States. 

"The state-by-state pattern is of interest in itself.  But it also
matters scientifically.  We wanted to study whether people's feelings
of satisfaction with their own lives are reliable, that is, whether
they match up to reality -- of sunshine hours, congestion, air quality,
etc -- in their own state.  And they do match.  When human beings give
you an answer on a numerical scale about how satisfied they are with
their lives, you should pay attention."

The top 10 :

1 Louisiana
2 Hawaii
3 Florida
4 Tennessee
5 Arizona
6 Mississippi
7 Montana
8 South Carolina