Why did free african americans need certificates of freedom?

They could be legally killed or sold.

Explanation:

Free African-Americans required a certificate to verify their freedom because there were many people willing to sell them. Seeing an African American walking around town wasn't common unless they were collecting water or running errand for their owners. So, naturally people grew suspicious.

Also, many runaway slaves could say that they were free. And, there would be no way to verify that if there were no certificates .

Slavery was truly a terrible time.

george calvert wanted maryland to be a colony where could live safely. because georgia's founders wanted a colony of small farms rather than large plantations, they originally banned under british law in the 1700s, people who owed money could be

the name of the theory is landmass theory.