Attorney General's Annual Report to Congress and Assessment of U.S. Government Activities to Combat Trafficking in Persons: Fiscal Year 2015 [open pdf - 2MB]
From the introduction:"Trafficking in persons, or human trafficking, is a pervasive problem in the United States and in nearly every other country in the world. Human trafficking has many manifestations, including forced labor, bonded labor, and sex trafficking. Those who engage in human trafficking are relentless in their attempts to find potential victims and exploit them for money and other personal gain. Human traffickers prey upon individuals who are vulnerable or who live on the margins of society--whether men, women, or children, and regardless of citizenship--and use a variety of means, including physical force, fraud, and coercion, to obtain and maintain control over their victims."
U.S. Department of Justice: http://www.justice.gov/