In 1E we had only 1 PC ever crest 20th level, though we had a number of others in the 17-19 kind of range after 10-15 YEARS of play. That of course was before "epic" was invented. It was "epic" just by the things our characters did.
In 2E, I can't remember. Campaigns tended to die out just a little too frequently to maintain a long-term PC so low teens was generally the highest we had. But they got there a little faster because of changes in the XP awards structure in the game.
In 3E the first campaign I ran went for about a year, year and a half and took the PC's to high teens in levels again in a small fraction of the time it would have taken to do so in older editions. But I wouldn't call it even "near-epic" because "Epic" was never really the goal. In point of fact, an overarching goal that I had set for the campaign at the outset was that it would begin, play out, and reach a CONCLUSION, preferably before PC's reached 20th level.