On December 18, 1865, the Thirteenth Amendment to the United States Constitution was ratified, officially abolishing slavery in the United States. The amendment was passed by the U.S. Senate in April of 1864, and then sent to the states for ratification. It was finally ratified by three-fourths of the states on December 18, 1865, and declared in force on December 18, 1865. This momentous event marked the end of a centuries-long struggle for civil rights and equality. The Thirteenth Amendment not only abolished the practice of slavery, but also prohibited the use of involuntary servitude as a form of punishment for a crime. It was a major step forward in the nation’s long-term effort to recognize the civil rights of all its citizens.