The laws for selling wine in U.S. market are quite complicated. The wine import & export business is heavily regulated by federal government and each individual state.
For example you can check the following resources about importing wine to U.S.A.:
If you are looking for someone who can lead you through the whole process please visit weinherr.com.
The service is free for small wineries from anywhere in the world. Weinherr will process all paperwork so you wine can be sold in the U.S. market. They will also help with market research, setting the correct pricing, obtaining warehouse and distribution.