In the eyes of the board of trustees, going coed could help stabilize the school's finances as interest in all-women schools wanes.
But when officials floated the idea last month, it drew a sharp response. Online petitions and campus protests decried the move, angry e-mail flooded in, one alumnae group even hired a lawyer to try to discourage the board by citing legal concerns.
Saturday morning, an agitated crowd of some 400 students, alumnae and their supporters greeted the board's announcement by drowning out trustees president Jolley Christman as she tried to explain.
"Today we begin to heal. We begin to write the next chapter in our history," Christman said, barely audible over the shouting.
Christman said the 27-2 vote followed 2 1/2 years of study. The board determined coeducation was the best way to preserve the school's mission of high academic standards for undergraduate students and said a co-educational version of Randolph-Macon would emphasize global honors programs.
Interim President Ginger Worden told the students and supporters, "Do not, I implore you, turn your back on this college," but many in the crowd swiftly turned their backs on her in response.
"I'm sad. I'm really sad," said Gabriella Medina, a freshman from Puerto Rico. "If we can't reverse this, I guess I'm going to transfer."
But Worden told CBS News correspondent Joie Chen that because less than 3 percent of college-bound high school students will even consider a single-gender college, studies showed that Randolph-Macon would have had to close its doors without making the move.
"Eventually we would have to go out of business," Worden told Chen. Before how long? "Well, ten [years] would be the outside number."
Even with substantial tuition discounts for 99 percent of its students, Randolph-Macon's enrollment has been dropping for 20 years.
Before Saturday's vote, supporters of single-gender education gathered on campus, many wearing yellow T-shirts distributed by the Students' Coalition to Preserve Woman's Education. A red-brick campus wall was lined with bedsheets turned into banners, one reading: "115 Years of Women Can't Be Wrong."
College officials expected resistance but said the move was necessary. Enrollment this fall was about 700, down from a student body of nearly 900 in the 1960s.
Worden said the school has had to dip into its $140 million (euro110.12 million) endowment for operations because of the large financial incentives required to attract good students.
Across the United States, only about 60 women's colleges remain, from nearly 300 in the 1960s, according to the Women's College Coalition.
To go coed, the school must now adopt a new name — there already is a Randolph-Macon College, a former men's school in Ashland. Christman hoped a task force would have a name to suggest this fall.