Final answer:
The Sixteenth Amendment was necessary due to the need for a new source of revenue for the federal government. Before the amendment, heavy reliance on tariffs had adverse effects on the working poor. The introduction of a federal income tax through the amendment provided a more equitable and sustainable solution.
Step-by-step explanation:
The conditions that preceded the Sixteenth Amendment and made it necessary were primarily related to the need for a new source of revenue for the federal government. Before the amendment, the government relied heavily on tariffs, which led to increased prices for goods and affected the working poor. The introduction of a federal income tax through the Sixteenth Amendment provided a more equitable and sustainable means of generating revenue.