Kofi - What happened next
Kofi grew to an adult and had a child with another slave. He then had family ties and other people to consider so did not run away as planned. One day, when his son had grown, he saw a huge group of people moving towards the plantation and heard from them that slavery has been abolished for several years. The new master used a gun to try to stop them leaving but without success. Kofi and his family left with the other ex-slaves.
Late 19th century wooden statue

This is a late 19th century wooden statue. It shows an enslaved African breaking free of their chains.
Child
It was difficult to form and maintain a family (slaves were sold, separated or died) but many slaves did, particularly in North America where slaves lived long enough to reproduce and grow in numbers.
Abolished
The slave trade was abolished in the United States from 1 January 1808 but slavery itself did not end until 1865. Many white people thought that life for black people would instantly improve when the trade ended but it did not. White people, many of who believed that they were racially superior to black and mixed race people, just developed new ways to discriminate, many of which are still used today.