In the spring of 1749, the billions-strong swarm of cicadas known today as Brood X emerged from the ground in rural Maryland, much to the fascination (and horror) of a 17-year-old Black tobacco farmer named Benjamin Banneker, who believed they were a plague of locusts.

“The first great Locust year that I can Remember was 1749,” wrote Banneker decades later in his astronomical journal. “I was then about Seventeen years of age when thousands of them came and was creeping up the trees and bushes, I then imagined they came to eat and destroy the fruit of the Earth, and would occasion a famine in the land. I, therefore, began to kill and destroy them, but soon saw that my labor was in vain, therefore gave over my pretension.”

Banneker, born a free man in 1731, went on to prominence as a brilliant self-taught mathematician, astronomer, surveyor and naturalist. At 22 years old, he built a clock entirely out of wood after seeing how a pocket watch functioned. The hand-carved wooden clock kept accurate time for 40 years.

Later in life, Banneker assisted his neighbor George Ellicott in the original land survey of the District of Columbia by calibrating Ellicott's field clock using the movement of the stars. In 1791, Banneker sent his almanac—one of the first published in America—to Secretary of State Thomas Jefferson, along with a letter pleading for freedom and equal rights for all Black Americans.

But for all of Banneker’s accomplishments, he’s rarely credited with being among the first scientific observers to calculate the 17-year life cycle of the remarkable periodical cicada, the longest-living insect on the planet.

“History books talk about the wooden clock and the survey of DC, but there’s hardly any information regarding the work that he did with the cicada,” says Janet Barber, who along with her husband Asamoah Nkwanta, published a 2014 paper that was the first to document Banneker’s handwritten notes on the cicada.

After witnessing that first memorable cicada swarm in 1749, Banneker closely observed three more emergences during his lifetime (1766, 1783 and 1800) and summarized his findings in his handwritten astronomical journal, a copy of which Barber and Nkwanta obtained from the Maryland Center for History and Culture.

“So that if I may venture So to express it,” wrote Banneker in June 1800, “their periodical return is Seventeen years, but they, like the Comets, make but a short stay with us–The female has a Sting in her tail as sharp and hard as a thorn, with which she perforates the branches of the trees, and in them holes lays eggs. The branch soon dies and fall, then the egg by some Occult cause immerges a great depth into the earth and there continues for the Space of Seventeen years as aforesaid.”

Barber and Nkwanta say it was nothing short of “thrilling” to read Banneker’s discovery in his own “immaculate” script. Banneker, whose father was formerly enslaved and mother was of mixed heritage, was taught to read and write by his grandmother. He occasionally attended schools run by Quakers, who were ardent abolitionists. Banneker wasn’t introduced to astronomy until he was 57 years old and borrowed some astronomical equipment and texts from Ellicott, a prominent Quaker businessman.

Banneker immersed himself in the study of astronomy and conceived of writing an astronomical almanac to prove the intellectual capacity of Black people, free or enslaved. With the backing of the Ellicotts and other abolitionists, Banneker published his almanac and sent a copy to Jefferson, who maintained a famously conflicted attitude toward slavery. Jefferson was duly impressed.

“No body wishes more than I do to see such proofs as you exhibit,” Jefferson wrote to Banneker, “that nature has given to our black brethren, talents equal to those of the other colours of men, and that the appearance of a want of them is owing merely to the degraded condition of their existence both in Africa and America.”

Banneker died in 1806 a month shy of his 75th birthday. Tragedy struck during his funeral when someone set his cabin on fire along with most of his personal journals and papers. Luckily, the Ellicotts were in possession of Banneker’s handwritten astronomical journal, which the family’s descendants gifted to the then Maryland Historical Society in 1987. Barber and Nkwanta began their research into Banneker’s cicada writings in 2004, driven by a desire to shine a light on the often overlooked contributions of Black scientists.

“I want children in school today to know about him and recognize Benjamin Banneker as a scientist, astronomer and mathematician,” says Barber, “and to know that he, too, was part of the discovery of the emergence of the cicada and how they behave.”

In his journal, Banneker concluded his entry on the cicadas by describing the musical cacophony produced by a horde of mating insects:

“I like to forgot to inform, that if their lives are Short they are merry, they begin to Sing or make a noise from the first they come out of Earth till they die, the hindermost part rots off, and it does not appear to be any pain to them for they still continue on Singing till they die.”