The entire first section of the 14th amendment was basically copied and condensed from the Civil Rights Act of 1866. The equal-protection clause is basically a rewriting of the requirement from the Act saying that all citizens, black or white, shall have the same right "to full and equal benefit of all laws and proceedings for the security of person and property, as is enjoyed by white citizens".
So basically "protection" had to do with, well protection. I suppose that makes too much sense in today's day and age, where anyone who isn't an abortionist is branded as a right winged radical.
I suppose that makes too much sense in today's day and ageYup, obviously we're not qualified to sit on the high court, if all we do is read the document without inventing new meanings. Buncha yahoos we are. ;-)