Educational Facilities & Population
There are over 105,000 school sites in the United States collectively servicing 55.4 million students.
— American School Directory

Employment
In the United States, K-12 Education accounts for 8 million directly related jobs, or 5.2% of the nation’s workforce – 3.6 million are employed as elementary and secondary school teachers and 4.4 million as other professional, administrative, and support staff.
— NCES Digest of Education Statistics: 2010
— U.S. Bureau of Labor Statistics Dec. 12, 2011

Income / Time invested
Among “professionals,” Educators are ranked 61 on a scale of 100; averaging $42,007.00 per year.
— PayScale 12 Dec 2011

Of 27 high performing countries, U.S. Teacher pay ranks 22nd; and of teachers with 15+ year experience, they earn less than 60% of the average pay of other full-time college-educated workers, unlike the 80-100 % in other countries.
— Building a High Quality Teaching Profession, OECD, 21 Nov 2011

Community
On average, each school site employs over 76 individuals in 12,000 thousand communities across the U.S.   — National Center for Educational Statistics
— American School Directory

Schools directly affect a community’s vitality. Americans rank quality of public schools second only to crime when deciding where to live. (A 1% increase in avg. test scores equals a 0.5-1% increase in property values.)
— “The Impact of Educational Quality on the Community” by Rand Education
— National Association of Realtors (NAR)

Investment
About $115.4 billion or 3.3% of 2010 U.S. (Federal) gross domestic budget was spent on K-12 education (down from 4.6% in 2009 & 5.9% in 2008).
— U.S Census Bureau Statistical Abstract (2012)

* Some of the above is extrapolated data