• U.S. Customs and Border Protection keep illegal goods from entering the country.security fence image by MAXFX from Fotolia.com
  
  Whenever you return from a trip abroad, you will go through United States Customs at the border or airport before you are allowed to reenter the country. U.S. Customs is responsible for preventing illegal goods, agricultural products or people from entering the country. When traveling abroad, it is best to recognize and understand the restrictions of what you can bring back to the United States to smoothly pass through customs.
  
  

Food

• It is not legal to bring agricultural products into the United States, according to U.S. Customs and Border Protection. Fresh items such as meats, cheeses, vegetables, fruit and other vegetation must be discarded before entering the country. These items are restricted in an effort to prevent pests or other meat or plant-borne diseases from entering the country. Foreign diseases and pests can have a negative economic impact if they infect American livestock or crops.
  
  

Medication

• It is illegal to bring any prescription drug into the United States not approved by the United States Food and Drug Administration, according to the Federal Food, Drug, and Cosmetic Act. However, if the person purchased the drug because of a serious illness and no effective treatment exists in the United States for the illness, he may receive dispensation if he agrees to not distribute the drug.
  
  

Cuban Cigars

• According to the U.S. Customs and Border Protection, there has been an increase in interest in Cuban cigars in recent years. A ban on importing them, whether for personal use or not, still exists in the U.S., making it illegal to enter the United States with Cuban cigars. Cuban cigars, even if you purchase them in another country like Mexico, Canada or Europe are still banned. Beyond Cuban cigars, any goods of Cuban origin are not permitted through customs.
  
  

Other Items

• Customs bans other items from entrance into the U.S. as well. For example, you cannot bring in absinthe, ivory and tortoise shell products. Live birds will be quarantined until they are deemed safe. Counterfeit and illegal items like designer purses, will be confiscated if you attempt to bring them into the U.S.