Final answer:
The question about a tax being eliminated in 1979 doesn't correspond with specific information in the references provided. However, a key tax reform occurred in 1986 with President Reagan, simplifying the tax code and eliminating many deductions and shelters.
Step-by-step explanation:
The tax type that was eliminated completely in 1979 is not directly mentioned in the provided reference information. However, we can infer that the question may be alluding to changes made to the federal income tax system. One significant tax-related change in the late 20th century was the Tax Reform Act of 1986, which simplified the tax code and eliminated various tax shelters and deductions previously used to illegitimately reduce one's tax burden.
President Reagan's administration was known for making sweeping changes to the tax code, including an overhaul that exempted millions of people with low incomes and eliminated many deductions. The 1986 reform, in particular, reduced the highest tax bracket and raised the minimum rate, thereby reducing the number of different brackets in between. Furthermore, prior to this period, 'bracket creep', which affected taxpayers due to inflation, was eliminated in 1981 when the income levels for higher tax rates were indexed to rise with inflation.