That man, according to an article being published on Saturday by the Yale Alumni Magazine, was Richard Henry Green. Born in 1833 to a local bootmaker who helped found St. Luke’s Episcopal Church in New Haven, he sat for the entrance examination and was admitted in 1853. Undergraduates did not have majors in those days, so Mr. Green, along with his 100 or so classmates (in what was at the time America’s largest college), read history, philosophy, literature and the like. He lived at his family’s home but he appears to have been active in campus life, joining the literary society Brothers in Unity as well as the fraternity Sigma Delta.

Mr. Green was awarded a bachelor of arts degree in 1857 and began teaching school in nearby Milford. From there he went to Vermont to teach at the Bennington Seminary. Mr. Green studied medicine at Dartmouth and served in the navy from 1863 until the end of the Civil War. Along the way, he married Charlotte Ann Caldwell of Bennington, Vt., and had a daughter, also named Charlotte. And then in 1877, while living with them in the town of Hoosick, N.Y., he died of what an obituary described as “disease of the heart.”

His distinction might have been lost to history but for Rick Stattler, an Americana specialist at Swann Auction Galleries in New York. He took an interest in a collection of 95 documents from the late 19th century that a dealer brought in. The items were not immediately remarkable, he said, just some family letters and personal receipts. But as Mr. Stattler began looking around, he came across a reference to Richard Henry Green in an ancestry.com family tree called African American Graduates of Old Yale.

From there he found a reference to Mr. Green in the American Educational Annual of 1875, which noted: “Five colored men have been graduated from the different schools of Yale. The first was Richard Henry Green of the class of 1857.” (Another was Cortlandt Van Rensselaer Creed, who in the same year graduated from the Yale School of Medicine.)

Yale officials have since confirmed Mr. Stattler’s findings.

Edward Bouchet, who graduated summa cum laude and was inducted into Phi Beta Kappa, was celebrated in his day as a pioneer. According to Judith Schiff, Yale’s chief research archivist, “a campus periodical at the time talks about him coming as the first — isn’t it wonderful that he’s here and we hope he can make a good record for his race.”