Tom;
Interestingly, in the early 70s the USGA had very similar yardages.
Up to 250 - Par 3
250 - 474 - Par 4
475 & Up - Par 5
Amazingly, there wasn't much change between 1930 & 1975, or even 85, really.
Now a 474 yard par four seems almost quaint for top-level players.