There aren't any legitimate college football national titles prior to 1998 (or arguably 2014 or even 2024), so any year that you finished with 1 or 0 losses, just claim it.

And not to make anyone uncomfortable, but does anyone really think any all-white Southern team prior to 1970 was actually the best in the country? Alabama claims national titles from 1961, 1964, and 1965 (playing only Southern teams in each year), but I doubt they would beat the best integrated Northern team or the SWAC champion either.