Biography of African American Astronomer Benjamin Banneker

Illustrated portrait of American author, astronomer, and farmer Benjamin Banneker (1731 - 1806), mid to late 18th century.(Photo by Stock Montage/Getty Images)
Stock Montage / Contributor/ Archive Photos/ Getty Images

Benjamin Banneker was an African American astronomer, clockmaker, and publisher who was instrumental in surveying the District of Columbia. He used his interest and knowledge of astronomy to create almanacs that contained information about the motions of the Sun, Moon, and planets. 

Early Life

Benjamin Banneker was born in Maryland on November 9, 1731. His maternal grandmother, Molly Walsh, emigrated from England to the colonies as an indentured servant in bondage for seven years. At the end of that time, she bought her own farm near Baltimore along with two other enslaved people. Later, she released those people from their bondage and married one of them. Formerly known as Banna Ka, Molly's husband had changed his name to Bannaky. Among their children, they had a daughter named Mary. When Mary Bannaky grew up, she also "purchased" an enslaved man, Robert, who, like her mother, she later freed and married. Robert and Mary Bannaky were the parents of Benjamin Banneker.

Molly used the Bible to teach Mary's children to read. Benjamin excelled in his studies and was also interested in music. He eventually learned to play the flute and violin. Later, when a Quaker school opened nearby, Benjamin attended it during the winter. There, he learned to write and gained a basic knowledge of mathematics. His biographers disagree on the amount of formal education he received, some claiming an 8th-grade education, while others doubt he received that much. However, few dispute his intelligence. At the age of 15, Banneker took over the operations for his family farm. His father, Robert Bannaky, had built a series of dams and watercourses for irrigation, and Benjamin enhanced the system to control the water from the springs (known around as Bannaky Springs) that supplied the farm's water.

At the age of 21, Banneker's life changed when he saw a neighbor's pocket watch. (Some say the watch belonged to Josef Levi, a traveling salesman.) He borrowed the watch, took it apart to draw all its pieces, then reassembled it and returned it running to its owner. Banneker then carved large-scale wooden replicas of each piece, calculating the gear assemblies himself. He used the parts to make the first wooden clock in the United States. It continued to work, striking each hour, for more than 40 years.

An Interest in Watches and Clock Making:

Driven by this fascination, Banneker turned from farming to watch and clock making. One customer was a neighbor named George Ellicott, a surveyor. He was so impressed with Banneker's work and intelligence, he lent him books on mathematics and astronomy. With this help, Banneker taught himself astronomy and advanced mathematics. Starting about 1773, he turned his attention to both subjects. His study of astronomy enabled him to make the calculations to predict solar and lunar eclipses. His work corrected some errors made by experts of the day. Banneker went on to compile an ephemeris, which became the Benjamin Banneker Almanac. An ephemeris is a listing or table of the positions of celestial objects and where they appear in the sky at given times during a year. The Almanac included an ephemeris, plus other useful information for sailors and farmers. Banneker's ephemeris also listed tables of tides at various points around the Chesapeake Bay region. He published that work yearly from 1791 through 1796 and eventually became known as the Sable Astronomer.

In 1791, Banneker sent then Secretary of State, Thomas Jefferson, a copy of his first almanac along with an eloquent plea for justice for African Americans, calling on the colonists' personal experience as "slaves" of Britain and quoting Jefferson's own words. Jefferson was impressed and sent a copy of the almanac to the Royal Academy of Sciences in Paris as evidence of the talent of Black people. Banneker's almanac helped convince many that he and other Black people were not intellectually inferior to white people.

Also in 1791, Banneker was hired to assist brothers Andrew and Joseph Ellicott as part of a six-man team to help design the new capital city, Washington, DC. This made him the first African American presidential appointee. In addition to his other work, Banneker published a treatise on bees, did a mathematical study on the cycle of the seventeen-year locust (an insect whose breeding and swarming cycle peaks every 17 years), and wrote passionately about the anti-slavery movement. Over the years, he played host many distinguished scientists and artists. Although he had predicted his own death at age 70, Benjamin Banneker actually survived another four years. His last walk (accompanied by a friend) came on October 9, 1806. He felt ill and went home to rest on his couch and died.

Banneker's memorial still exists at the Westchester Grade School in the Ellicott City/Oella region of Maryland, where Banneker spent his entire life except for the Federal survey. Most of his possessions were lost in a fire set by arsonists after he died, although a journal and some candle molds, a table, and a few other items remained. These remained in the family until the 1990s, when they were purchased and then donated to the Banneker-Douglass Museum in Annapolis. In 1980, the U.S. Postal Service issued a postage stamp in his honor.

Edited by Carolyn Collins Petersen.

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Greene, Nick. "Biography of African American Astronomer Benjamin Banneker." ThoughtCo, Sep. 6, 2020, Greene, Nick. (2020, September 6). Biography of African American Astronomer Benjamin Banneker. Retrieved from Greene, Nick. "Biography of African American Astronomer Benjamin Banneker." ThoughtCo. (accessed May 29, 2023).