The record is 72,748,970 set in 2000, but after Tuesday the majors had drawn 60,035,551 fans, reports USATODAY.com.
"It's been a remarkable year, and no matter how you measure - TV ratings, radio, attendance - baseball has never been more popular," commissioner Bud Selig said.
The Anaheim Angels, Los Angeles Dodgers, Philadelphia Phillies, San Francisco Giants, Chicago Cubs, Houston Astros and St. Louis Cardinals are all in line to draw 3 million fans.
The Boston Red Sox would hit 3 million, but Fenway Park holds just over 35,000, leaving it impossible for the team to hit the magic figure even though the stands are full for every game.
According to MLB, 14 teams have drawn at least 2 million, and every team except the Montreal Expos has reached 1 million.
Selig said the attendance is improving because baseball has been building on a great 2003 postseason, interesting off-season story lines — including the Alex Rodriguez trade — improved marketing, two new ballparks and parity in the standings.
"There's hope in Detroit, and that's why the Tigers' attendance is up," Selig said. "There's hope in a lot of cities."
Eight clubs have shown an attendance drop, including the Toronto Blue Jays (down 84,000) and Kansas City Royals (down 89,000), but most clubs' lower numbers are minimal, he said.
