What is the United States Customs Service (USCS)?

The United States Customs Service (USCS) was a federal government agency, established on July 31, 1789, following the American Revolutionary War. This agency was responsible for collecting import tariffs and other border security duties. For more than 100 years, it was the primary source of revenue of the young nation. However, in 2003, during Homeland Security Reorganization, this agency was replaced by the Bureau of Customs and Border Protection, a comprehensive border security agency.