The Answer:

As of 2003, 2.2% of U.S. children were homeschooled. Roughly 54% of those homeschooled children were in two-parent households in which only one parent was in the labor force. The top reason for homeschooling, cited in 85.4% of cases, was due to concern about the school environment; this included concerns about safety, drugs, and negative peer pressure.

For more information, see Characteristics of Homeschooled Students and Parents' Reasons for Homeschooling.

—The Fact Monster