A shareholder sued to block Union Pacific from paying the new federal income tax, arguing the 1913 tax was still an unapportioned direct tax forbidden by Article I. Chief Justice White held that the Sixteenth Amendment did not create a new power to tax but removed the apportionment requirement Pollock v. Farmers' Loan & Trust (1895) had imposed on income taxes. Congress could therefore tax income 'from whatever source derived' without apportionment among the states by population. Brushaber cleared the constitutional runway for the modern income-tax system and every federal revenue statute that followed.