I have a neighbor who also has a butterfly garden. Several days ago one of their caterpillars formed its chrysalis and she and her girls cut the little branch off, stuck it in a pot of dirt, and brought it indoors to watch it. She called me this weekend and said their butterfly had emerged! It is an Eastern Black Swallowtail. You can see the chrysalis still on the branch.
After a little while, they carried the pot down to my butterfly garden where I have some nectar plants.