On Tuesday morning, a neatly-dressed Mary Shodiya took the subway to Wall Street from Brooklyn, parked outside the New York Stock Exchange, and propped up a sign, which, in neat black letters, said: “Hello, I’m Mary, I’m brilliant. Columbia University agrees. All I need is a loan. Name your interest rate.”

By yesterday afternoon, she had more than $13,000 in donations, and a story that her new classmates starting Columbia may find hard to believe.

But this story is true and it goes like this: By Tuesday afternoon, the 19-year old native of Nigeria had intrigued a few passers-by. It was nearing the end of the day, and the prospect of meeting her fund-raising goal – $4,000 for her first tuition check – was growing dim.

Then, in a happenstance usually reserved for the movies, she met Judith Aidoo, a Harvard Law School graduate and Wall Street veteran, who now owns an investment management company.

Ms. Aidoo, 41, asked some basic questions and told Ms. Shodiya to fax her the Barnard College acceptance letter along with proof of her denied financial aid, and the budget for her first year of school. Barnard, a women’s college, is part of Columbia University.

Within 48 hours of verifying Ms. Shodiya’s story and identity, Ms. Aidoo, who lived in Ghana, her father’s home country, in her teens and has worked and traveled throughout West Africa, had the story on several list-servs and had raised more than $10,000, with donations and pledges from business associates, colleagues, and friends from around the globe. That amount is now about $13,000 and is still growing.

“It was the wording of the sign that probably caught me first,” Ms. Aidoo said yesterday. “She was smart, she was young, she was well put-together. It was not like she was begging. I knew she had guts. It reminded me of something I would have done in my youth. She was really going for it.”

The two women met again in front of the stock exchange Friday and traveled up to Barnard together to talk to the bursar. They turned over a check for $7,450, but discovered they needed another $8,000 by Labor Day to get Ms. Shodiya enrolled in fall classes.

Ms. Aidoo, who has a vast network of business, philanthropic and African-focused organizations, is confident that they will be able to pull it off. Ms. Shodiya is moving into a Columbia dorm today to begin orientation with more backing than she could have ever imagined.

“I was desperate,” she said yesterday. “I went hoping for a miracle. And, I got lucky. I found a guardian angel.”

Ms. Shodiya, who has been working in a cell phone store and living with her aunt in Brooklyn, deferred her Barnard acceptance last year because she didn’t have the tuition.

She has been living in America since age 11. She graduated from high school in Maryland with 4.05 grade point average, scored an impressive 1370 on her SATs, and was adopted here by her uncle. But she was not eligible for financial aid because she does not yet hold a Green Card.

On a lark, she approached two people in Union Square who had a sign that read: “Talk to me” and told them her story. It was on their suggestion that she tried Wall Street. Her gumption has prompted nearly 30 people and organizations, including Essence magazine, to dig into their wallets to help.

“Education is so fundamentally important, it’s crucial, especially for gifted kids with potential,” said the top donor, Kneeland Youngblood, who runs a private equity firm in Dallas called Pharos Capital Group and who contributed $2,500.

“I think anyone who has the chutzpa and is so desperate to get an education is worth supporting,” said Whitney Tilison, a hedge fund manager in Manhattan who donated $250.

Ms. Shodiya, whose parents live in Nigeria, is planning a double major in biology and pan-African studies with a minor in French. She said she is hoping to start a summer program in Africa for children. She is giddy with excitement and is calling the situation “amazing.”

Donor Patrick Okigbo, who works at Citigroup and runs an organization called VisionNigeria, said he was in a similar situation when he came from Nigeria three years ago to go for his master’s in business administration. The opportunity to support someone else was one he could not pass up, he said. He also said that, aware of the scam e-mails involving Nigeria and bank accounts, he was careful to verify that this was for real.

“Whose knows, she might be the answer for Nigeria,” Mr. Okigbo said. “And, the choice of the New York Stock Exchange was a stroke of genius.”