The Cabbage White is the most common butterfly in central New Jersey.  Most years, there would usually be three or four, and as many as a dozen in my garden at the same time.  I didn't see more than two at any one time in my garden in 2002.  In 2003, there were approximately 50 of them in my garden at one time!  The female has two black spots on its forewings above, the male only has one.  Some of them have a slightly yellowish appearance like the one pictured on the bottom right.  I have seen them laying eggs on my Dame's Rocket plants.