Understanding the 16th Amendment
The text of the 16th Amendment is as follows:
The Congress shall have the power to lay and collect taxes on incomes, from whatever source derived, without apportionment among the several States, and without regard to any census or enumeration.
You are highlighting the wrong words. The change was in the words "from whatever source derived." The 16th Amendment was a response to the Supreme Court ruling Pollock v. Farmers' Loan & Trust Co. in 1894. In that ruling the court did rule that all income taxes were unconstitutional (there had been an income tax in 1861) but rather held that income taxes on rents, dividends, and interest were direct taxes and thus had to be apportioned among the states on the basis of population.