New Jersey passed a law providing for the “gradual emancipation of slaves” on February 15, 1804, and in doing so became the last Northern state to begin the process of ending enslavement within its borders. Using the language of bondage, the 1804 act provided that children of enslaved people born after July 4, 1804, would be freed when they reached the age of 21 for women and the age of 15 for men.

SOURCE: https://calendar.eji.org