Were Income taxes really illegal before the 16th amendement because when i read the Constitution before the 16th amendement it says “No Capitation, or other direct, Tax shall be laid, unless in proportion to the Census or Enumeration herein before directed to be taken.” This doesn’t sound like a ban on direct taxes but just a restriction on the manner by which they can be imposed.
If you read the Constitution the way it was ratified, then yes, income taxes were unconstitutional. That is why the 16th was added to the Constitution. The Republicans introduced an income tax in the 1860s only to have it knocked down by the Supreme Court about 20 years later. Direct taxes were assumed to be taxes similar to a stamp act or something of that nature and even Alexander Hamilton said that a direct tax was too messy and complicated to use.