Molly Walsh, a white woman, emigrated from England to the colony Maryland as an indentured slave in bondage for seven years. When her servitude ended, Molly purchased a farm along the Patapsco River near Baltimore. and two slaves. In time she set the slaves free and married one of them, a man named Bannaky (changed from Banna Ka). They had several children, one a daughter named Mary. Mary Bannaky grew up, purchased a slave, Robert, whom she later married and lived on the family farm. On Nov. 9, 1731, a son, Benjamin, was born to Robert and Mary Bannaky.

Using the Bible, Molly Bannaky taught Mary's children to read, and soon after, Benjamin would read the bible to his mother and grandmother. For those times, life was good to this little community, but work was hard, but not challenging to Benjamin. He learned to play the flute and the violin, and when a Quaker school opened in the valley, Benjamin attended it during the winter where he learned to write and elementary arithmetic. He had an eighth-grade education by time he was 15, at which time he took over the operations for the family farm. He devised an irrigation system of ditches and little dams to control the water from the springs (known around as Bannaky Springs) on the family farm. Their tobacco farm flourished even in times of drought.

Banneker became fascinated with the patent watch of a friend, Josef Levi. Levi gave Benjamin the watch and he took it apart to 'study its workings." Banneker then carved similar watch pieces out of wood to make, in1752, a wooden clock. Due to its precision (it struck every hour, on the hour, and continued to do so nearly forty years) the clock brought fame to young Banneker. Thus he began a watch and clock repair business. Further, he helped another famous Marylander, the industrialist Joseph Ellicott, to build a complex clock. Banneker and the Ellicott brothers became friends.

Joseph Ellicott was an amateur mathematician and astronomer and lent Banneker books on astronomy and mathematics as well as instruments for observing the stars. Banneker taught himself astronomy and advanced mathematics and, in 1773, he began to devote serious attention to both subjects. He successfully predicted the solar eclipse that occurred on April 14, 1789, contradicting the forecasts of prominent mathematicians and astronomers of the day.

Banneker's habits of study appear odd to the non-scientist. It is said that on many nights, he would wrap himself in a great cloak and lie under a pear tree and meditate on the revolutions of the heavenly bodies. He would remain there throughout the night and take to his bed at dawn.

As reported in the Georgetown Weekly Ledger March 12, 1791, when Banneker was 60, he was appointed, by President George Washington, to a three man team of surveyors headed by Major Andrew Ellicott, Joseph's cousin, to survey the future District of Columbia. Banneker, the paper said, was "an Ethiopian whose abilities as surveyor and astronomer already prove that Mr. [Thomas] Jefferson's concluding that that race of men were void of mental endowment was without foundation."

Banneker and Ellicott worked closely with Pierre L'Enfant, the architect in charge. However, L'Enfant could not control his temper and was fired. He left, taking all the plans with him. But Banneker saved the day by recreating the plans from memory.

Also in 1791, Banneker created and published his acclaimed Pennsylvania, Delaware, Maryland, and Almanac and Ephemeris. In 1792 Secretary of State Thomas Jefferson, white supremacist, and slave owner pronounced Blacks mathematically inferior. In response to Jefferson, Benjamin Banneker sent a copy of his almanac along with a twelve page twelve page letter to Secretary of State Thomas Jefferson requesting aid in improving the lot of American Blacks.

Banneker's Almanac's were compared favorable with Benjamin Franklin's Poor Richards's Almanac. However, in 1802 he stopped publishing his Almanac due to poor sales.

Banneker lived for four years after his almanacs discontinued. He published a treatise on bees, did a mathematical study on the cycle of the seventeen-year locust, and became a pamphleteer for the anti-slavery movement. He continued scientific studies by night and walked his land by day. He also continued to keep his garden. He hosted many distinguished scientists and artists of his day, and his visitors commented on his intelligence and on his knowledge of everything of importance that was happening in the country. As always, he remained precise and reflective in his conversations with others. His last walk (with a friend) came on October 9, 1806, he complained of being ill and went home to rest on his couch. He died later that day.