Let's say there was no ancient olympic boxing. No bareknuckle boxing. Instead, what if boxing started around the time that American Football started? The question is: Would the knowledge of the arts of boxing be where it is today without the pre-1880 manuals and history?
Boxing technique in many ways came from fencing techniques. The jab where one would step in with the punch, land, then step back out was described in perfect fencing form. In addition combat sports such as boxing were handed down from 17th century combat sports such as "gouging" where the winner would be the first to gouge his opponents eye out of its socket.
Rough and tumble on the frontier was as rough as anything got...no holds barred and eyes were a prize...in a fight to survive I can see it but not over being disrespected which happened alot