The primary responsibility of the U.S. Border Patrol is to ensure dangerous criminals do not enter the country. The officers with the Border Patrol also make sure people do not smuggle illegal things into the United States, according to the U.S. Customs and Border Protection.
In order to successfully do their jobs, all new Border Patrol agents must attend 13 weeks of training at the Border Patrol Academy. The Border Patrol works closely with other branches of law enforcement to keep illegal aliens out of the United States.
The Border Patrol is responsible for 6,000 miles along the Canadian and Mexican borders and 2,000 miles of water surrounding Florida and Puerto Rico. Border Patrol agents are always on duty. At the end of 2012, there were more than 21,000 Border Patrol agents and the agency is always hiring new recruits, according to the U.S. Customs and Border Protection.
Customs officers oversee the things travelers bring back from other countries to ensure everything is legal and the proper customs duty taxes are paid. Anything United States travelers come back with that they didn't leave the country with must be declared and is subjected to tariffs. Customs officers are always on the lookout for illegal items and are trained to spot smugglers.