Final answer:
The Sixteenth Amendment, ratified in 1913, allowed for a progressive federal income tax ranging from 1 percent to 7 percent. It was initially applicable to only the wealthiest Americans. Over time, the number of taxpayers and tax rates expanded as the revenue needs of the federal government grew.
Step-by-step explanation:
The question refers to the implementation of the first federal income tax in the United States after the ratification of the Sixteenth Amendment to the Constitution. The Sixteenth Amendment, which was a pivotal response to the need for consistent revenue for the federal government, was ratified in 1913 and subsequently allowed for the collection of an income tax directly from individuals without apportionment among the states by population. The amendment eliminated the constraints imposed by Article I, Section 9 of the Constitution, which had earlier complicated the taxation process.
The early tax rates following the amendment were indeed progressive and modest, starting at 1 percent and going up to a maximum of 7 percent for the wealthiest individuals. The Progressive Era's taxation policy aimed to levy taxes more heavily on the affluent part of society, in line with the ideals espoused by the Populists and Progressives. Moreover, only a small percentage of Americans, primarily those with higher incomes, could be subjected to these taxes initially. Over time, however, as the need for governmental revenue grew, both the tax rates and the number of people affected by federal income taxes increased significantly.