What is the "pursuit of happiness"?
Today many people seem to think that the right to pursue happiness is the right to have a happy, peachy life. Therefore, they think they have the right to free education, health care, social programs, etc.
On the contrary, the pursuit of happiness simply refers to "the right to pursue any legal activity as long as it does not infringe on the rights of others." Therefore, it is basically an extension of your right to liberty. You are free to do what you will as long as it doesn't infringe upon others' rights.