In the book The Millionaire Next Door, authors Thomas Stanley and William Danko examine the lives of Americans with seven figures in assets and reveal that in the main, most of them hit those levels -- while working in ordinary jobs -- by living fairly modestly and well within their means. They were, in fact, the sort of people you'd never suspect were rich, because they got rich precisely by not spending money like they were rich. Such wealth has a tendency to outlast the people who accrue it, and get passed on to heirs -- or to charities.

In this segment from Motley Fool Answers, hosts Robert Brokamp and Alison Southwick debut a series of profiles of people who nobody knew were rich until they donated or bequeathed fortunes to worthy causes. First up, Oseola McCarty, a washerwoman from Hattiesburg, Mississippi, whose frugal lifestyle and steady savings turned her into a philanthropic celebrity in her golden years.

A full transcript follows the video.

This video was recorded on July 10, 2018.

Robert Brokamp: Alison, it's no secret to longtime listeners that I'm a fan of The Millionaire Next Door, a book that was first published in 1996 by Thomas Stanley and William Danko. Basically, they looked at real-life millionaires to see how they lived. They found out that real-life millionaires don't live in big houses and have fancy cars. Actually, most of those people are not millionaires because they have such big debts. The real-life millionaires live in middle-class or lower neighborhoods, they drive ordinary cars, they don't live a flashy lifestyle.

While they focused on millionaires for the study, really, what they emphasized is the ability to cumulate above-average wealth given your circumstances. In fact, they even had a formula for it. But the thing is, you wouldn't know that these people have amassed a decent amount of wealth relative to their income because they live relatively simple lives, and they usually pass their wealth onto their kids or to charities. It's the cases of these charities where we sometimes learn about some people who surprisingly had accumulated a decent amount of money.

In the coming weeks, we're going to profile a few of these so-called philanthropists next door, starting with someone whose bequest was actually much less than a million dollars, at least initially. In this first installment, we'd like to introduce you to a woman named Oseola McCarty.

She was an African American woman born in 1908 in Hattiesburg, Mississippi. She lived with her mother, her grandmother, and an aunt. The women made a living by washing clothes, cooking, and cleaning houses. The washing was all done by hand. In the morning, they went out, built the fire, put the pot of water on, washed it by hand, and then they'd hang the laundry out on a line.

Alison Southwick: Oh, wow, and using lye and all kinds of horrible chemicals.

Brokamp: Yeah. Doing all the ironing with an iron that you put on a stove, all that stuff.

Southwick: Oh, hard work.

Brokamp: Right. Oseola started helping with the washing at a very early age, and she loved it. She was particularly careful about washing and ironing her own clothes for school. One day, her teacher asked her, "Who irons your clothes?" And Oseola said, "I do." So, the teacher hired her, and the word spread.

The children in a household where her grandmother worked had thrown out a doll buggy. Her grandmother brought it home and gave it to Oseola, and that became her piggy bank. That's where she'd deposit all her money. When she was 12, her aunt became sick and could no longer walk or work, so Oseola had to leave school in the sixth grade to help take care of her and help with the washing. She never returned to school.

One of her jobs was to walk around town and pay the family's monthly bills -- pay the grocer, pay the milkman, people like that. One day, she passed the bank and thought she should put some of the money there. She once said, "I went to the bank and deposited it. I didn't know how to do it. I went there myself, didn't tell Momma and them I was going."

For her entire working like, she washed clothes by hand. In the 1960s, she tried a washing machine and a dryer, but felt that the washer didn't rinse enough and that the dryer turned whites yellow, so she turned back to her scrubbing rag and just setting a fire every morning and doing the washing herself.

She lived in a small, simple house, never owned a car, pushing a shopping cart a mile each way to the local grocery store. She never married or had her own children, but she did regularly go to church and made sure that she put money in the collection plate each week. And, she kept putting money in the bank.

By the time she retired in her 80s, in 1995, her account was worth $280,000. Adjusted for inflation, that's almost $500,000. That alone is pretty remarkable. But then, with the help of her banker and a lawyer for whom she worked, she decided to donate $150,000 of it to the University of Southern Mississippi to create scholarships for lower-income African-American students, even though she never attended college. She never even visited the college, even though it's just a few blocks from her house.

Word got out about her donation, and 600 other people contributed to the fund, adding another $330,000. Then, she became a celebrity. She was on the David Letterman show, she was on Oprah. She was awarded an honorary doctorate by the University of Southern Mississippi and Harvard. It was the first time she'd ever been on a plane. She carried the Olympic torch through part of Mississippi as it made its way to Atlanta in 1996.

Southwick: She's 80-some years old when this is all happening?

Brokamp: Yes. She also won the United Nations Avicenna Medal for educational commitment, and Bill Clinton awarded her a Presidential Citizens Medal. She rang in 1997 by being the person who flips the switch for the ball to drop on Times Square. She said at the time it was the latest she'd ever stayed up in her whole life. It inspired Ted Turner, the creator of CNN, to donate $1 billion to charity. He said, "If that little woman can give away everything she has, then I can give a billion."

Most of her life, it was in a savings account or CDs. Eventually, the people at the bank convinced her to invest in some conservative mutual funds, so it grew a little bit more. They also convinced her, by the way, to buy an air conditioner for her house and cable TV. Fellow Fool Selena Maranjian has written about her. She wrote about her several years ago. One of Oseola's bankers wrote to Selena and said, "If we had been able to introduce her to equities earlier, she would have left millions instead of thousands."

Oseola died in 1999 at the age of 91. Today, at the University of Southern Mississippi, there's a residence hall named after her. According to articles from 2014, the Oseola McCarty Endowed Scholarship fund is worth more than $700,000. I emailed the university to ask what it's worth now, and they said they don't provide that value anymore, but they did say that through this year, approximately $480,000 has been distributed to 84 students.

Yeah. I'll close with four quotes from Osceola herself. A journalist from People Magazine asked why she didn't spend the money that she'd saved on herself. She answered that, "Thanks to the pleasure that comes from making the gift, I am spending it on myself."

She said, "I hear some people today have financial advisors to tell them how to save their money and what to spend it on, or people who want more of this or more of that to make them happy. They just can't get enough. Well, the Lord portioned out the good things in life to me just fine. Who needs any more?"

She also said, "I'm proud that I worked hard and that my money will help young people who worked hard who deserve it. I'm proud that I'm leaving something positive in this world. My only regret is that I didn't have more to give."

And finally, "I can't do everything, but I can do something to help somebody. And what I can do, I will do."