Background Information The us has had income tax laws since 1913. Income tax is a tax on the wages, salaries, profits, interest and rent received by a taxpayer within a definite period of time. In the us approximately one quarter of a middle class family's earnings goes to the government through the Internal Revenue Service (irs) in the form of taxes in Great britain about one third of a middle class family's income goes to taxesBackground Information The US has had income tax laws since 1913. Income tax is a tax on the wages, salaries, profits, interest and rent received by a taxpayer within a definite period of time. In the US approximately one quarter of a middle class family's earnings goes to the government through the Internal Revenue Service (IRS) in the form of taxes; in Great Britain about one third of a middle class family's income goes to taxes