The slim, faded volume tucked away in a rare-book store in Manhattan caught the eye of a browsing professor from Yale University one day in 1981. Henry Louis Gates Jr. impulsively paid $50 for the book, dated 1859 and titled: Our Nig; or, Sketches From the Life of a Free Black. "When I bought it, I assumed it was written by a white person about blacks during the middle of the 19th century and that it was one more fantasy like Gone With the Wind with darkies strumming the banjos out in the field," recalls Gates, 33. But after six months of careful research into the book's origin, Gates excitedly determined that Our Nig was the first novel in the United States published by a black. All the more intriguing, he learned, was the fact that the author was actually a black woman named Harriet Wilson.

Gates' discovery (scholars had previously believed that the first novel published in the U.S. by a black American was Clotelle by William Wells Brown in 1864) fulfills what he calls his "Christopher Columbus complex." It has also given new life to the long forgotten work. After the New York Times detailed Gates' findings, publishers bid furiously for the rights to reprint Our Nig. The winner, Random House, now has 17,500 copies in circulation.

For readers, Our Nig is a curious and floridly written novel about an indentured Northern black woman in the mid 19th century who is the product of an interracial marriage (the topic of miscegenation was taboo in those days). For Gates, the book was a personal quest which began with his first reading. In the preface, the author stated that she was black and appealed to "my colored brethren universally for patronage." "There was no reason," says Gates, "for a white person to pretend he or she was black in those days." Determined to know more about Wilson, Gates combed through documents all over the East Coast. He examined copyright information, census data, old newspapers and magazines, centering his efforts in Boston where the book was printed. Then, in June of 1982, one of Gates' students found a listing in the 1860 Boston census for a widow named Harriet Wilson with the letter B for black next to her name (a practice of the era).

Suspecting this was whom he was looking for, Gates next tried to find evidence of a son mentioned in the appendix to Our Nig. (Wilson wrote the book, she implies, to earn enough money to bring her boy back from a foster home.) Finally, one of Gates' colleagues found a death certificate for George Mason Wilson, son of "Mrs. H.E. Wilson," the name that appears on the copyright page of Our Nig. To Gates, this closed the case. But he was saddened to learn that George Mason Wilson died at age 7, six months after the book was published and long before his mother could have hoped to reap any profit.

Unraveling the Wilson case is one of many successes in Gates' career. The son of a worker in a paper mill in Piedmont, W.Va., he graduated summa cum laude from Yale, then won a Mellon scholarship to Cambridge University. After earning his doctorate in English literature from Cambridge in 1978 (the first black to do so), Gates embarked upon a career as an assistant professor in the Afro-American Studies and English departments at Yale. In 1981 his writings on black literary theory won Gates a prestigious award from the John D. and Catherine T. MacArthur Foundation. The $164,000 prize, spread out over five years, allows him, he says, the "financial and psychological freedom" to pursue obscure areas of literary theory.

Gates still maintains a full course load at Yale, where he lives on campus with his artist wife, Sharon Adams, a white woman, and their two daughters, Maggie, 3, and Liza, 19 months. A prolific writer as well as scholar, Gates currently has four books in various stages of prepublication, including another "lost" volume, a slave narrative published in 1815 by an African preacher.

For the moment, however, he's enjoying the excitement over Our Nig. "This poor woman Harriet Wilson is finally having her day," he chuckles. And so, say black scholars, is Gates. "Henry Gates," pronounces celebrated poet Maya Angelou, "discovered what was done and who did it. He is a wonderful mixture of Alex Haley and Sherlock Holmes."