By 1913, 36 States had ratified the 16th Amendment to the Constitution. In October, Congress passed a new income tax law with rates beginning at 1 percent and rising to 7 percent for taxpayers with income in excess of $500,000.
http://www.treasury.gov/education/fact-sheets/taxes/ustax.shtml
Once they have an independent source of tax revenue, the next step will be an international police force, with authority to make arrests and transport the arrested to the ICC.