Which amendment each person must be taxed fairly on the income he or she makes?

The 16th Amendment to the United States Constitution, ratified in 1913, grants Congress the authority to levy an income tax without apportioning it among the states based on population. This amendment ensures that individuals are taxed fairly on their income, allowing for a progressive tax system where higher earners pay a larger percentage. As a result, the 16th Amendment plays a crucial role in the federal government's ability to generate revenue through income taxes.