Why would a slaveholder want to keep a slave ignorant of such a simple thing as his birth date?
The power to enslave another class of people rests solely on the ability to bind them in ignorance. Specific to the birth-date of a slave, many second and third generation slaves had Caucasian fathers. In many instances, titles such as "master" and "father" would have been synonymous but the term "father" was forbidden among slave children. Depriving the slave of his birth-date was one of several methodical strategies, stripping both his identity and humanity. Remember both African Americans and Native Americans were once considered less human than their Euro- American counterparts. References involving the relationship between slavery and ignorance can be found in chapter six of the narrative. One of the primary themes of the narrative is the power of an education. The slaveholder understood the power the slave could possess with knowledge, the power to become as equal or usurp authority. Booker T. Washington also adopted the thematic approach of education in his narrative, Up From Slavery.
Slaveholders wanted to strip slaves of anything that might give the slaves a sense of identity. Slaves were considered to be animals void of emotions, thought, or personality. But slaveholders had to work at keeping the slaves at the level of animals. They would restrict them from learning, reading, writing - they changed their names and kept them from knowing anything of their history or background. By doing this, slaveholders hoped to keep slaves ignorant and downtrodden. If a slave knew his date of birth, then he would know his age, and knowing how old you are is a part of having an identity. If slaves developed an identity then they might gain the confidence to rise up against slaveholders.