Lisa Rimmert, age 16, of Keen, N.H., for her question:

WHEN DID THE INTERNAL REVENUE SERVICE START?

The Internal Revenue Service (IRS) was established by the United States government in 1862 to help pay the cost of the Civil War. The federal income tax system began in 1913 and the pay as you go plan went into effect in 1943.

The IRS is an agency of the United States Department of the Treasury. It collects income taxes, enforces tax laws and collects estate, excise, gift and other taxes. The money that the agency collects is called "internal revenue" because it comes from sources within the country.

Tax money pays for most of the federal government's activities, including national defense.

The IRS administers a 'tax system based on voluntary cooperation. The taxpayer fills out a form, called a tax return, stating his income and amount of tax he owes. Employers collect a withholding tax from each paycheck and send it directly to the IRS. If the taxpayer owes more money, he sends it with his return. If he has paid too much, the IRS issues a refund.