When Elizabeth Dean was four, her mother took her out of kindergarten to teach her at home because she could already read "Charlotte's Web" while other kids were just learning how to write the letter "C".
That was 10 years ago and homeschooling was "still on the fringe of acceptability," Elizabeth's mother Lisa Dean told AFP in between classes in the family home on the history of ancient Rome, the writings of Edgar Allen Poe, online geometry and English for Elizabeth, 14, and 11-year-old Teddy.
"Ten years ago, folks typically would list their reasons for homeschooling as religious reasons or wanting to fly under the government radar," she said.
But she gave up a well-paid job as a lawyer in Washington to become a stay-at-home mum who homeschools for academic reasons and because she is a self-avowed mother hen.
"I read the same things everyone else reads about what's happening in schools -- sexual activity, drugs, bullying, violence -- and don't feel that kids need to experience that," she said.
Dean hailed homeschooling for allowing children to choose topics they are interested in, within a set curriculum, and to advance at their own pace.
When Elizabeth, who goes by the nickname Bitsy, begins high school next term, she will enroll in Spanish and writing courses at the local community college, while continuing her homeschooling which will include an online trigonometry course for students two years older than she is.
Homeschooling dates back to colonial America, but lost ground when institutionalized schooling became compulsory in the mid-1800s.
At the height of the hippy culture in the 1960s, homeschooling enjoyed a renaissance as left-wingers seeking to buck the establishment taught their children themselves.
Christian conservatives were the next to embrace homeschooling, and "by 1990, 85 to 90 per cent of all homeschoolers came from the ranks of the religious right," Paul Petersen, a senior fellow at Stanford University's Hoover Institution, wrote in Education Next, which he edits.
The number of home-schooled children soared by 29 per cent between 1999 and 2003, from 850,000 to roughly 1.1 million, data from the National Centre for Education Statistics (NCES) show.
In Maryland, which keeps its own statistics on homeschooling, there were 2,296 home-schooled children in 1990, and more than 10 times that number -- 24,227 -- in 2006.
A survey conducted in 2003 by the NCES showed that the reason given most often by parents for homeschooling their children was the environment in traditional schools.
Just over 30 per cent of parents polled said they homeschooled their kids because of worries for their safety, about drugs or peer pressure.
Slightly less than 30 per cent said they chose to homeschool their children for moral or religious reasons and 16.5 per cent who said they were unhappy with the academics in traditional schools.
Tamara Bergen has homeschooled her two daughters for the past 15 years, partly because she wants to share her Christian values with them, but also because "families that educate at home have more flexibility with their schedules".
"You can teach to your child's level, abilities, pace, interests, gifts, and talents. Home education teaches students to be self-starters and independent learners," she says on her website theenterprisinghomeschooler.com.
The biggest criticism leveled at homeschooling is that it deprives children of social contact. "My sister said when we started this, 'You're going to turn your kids into freaks! They won't know how to behave!'" said Dean.
"But while socialization is a big problem in homeschooling, it's the opposite of what you might think: there's too much of it," she said as Teddy took a break from a history lesson to play in the classroom-basement of the family home with two friends.
"The kids are always together; the problem is finding time to do the book work," Dean said.
Bitsy and Teddy share their homeschooling credentials with the likes of the second-place finisher in this year's Scripps National Spelling Bee in Washington, 12-year-old Tim Ruiter, and US Olympic and World Cup skier Bode Miller, who was homeschooled during part of his elementary education years.
According to Teri Ann Berg Olsen, creator of the Knowledge House website, poet Robert Frost was home-schooled, and flight pioneers Wilbur and Orville Wright were often "allowed to stay home from school to work on their own projects".
After rolling around on two large exercise balls with his friends, Teddy sat down at the desk he shares with Bitsy in the basement and began sounding out spelling words.
Bitsy tucked into some online geometry, using headphones to block out the sounds of Teddy's lesson. It had just gone noon, and the school day -- that had begun four hours earlier over a bowl of oatmeal and an Edgar Allen Poe story -- was moving on.