Forty years ago, Bob Hall, a 23-year-old native of Belmont, won the inaugural wheelchair race of the Boston Marathon. He crossed the Boylston Street finish line in 2 hours 58 minutes in a chair that, in comparison with today’s modern race chairs, seemed to have been liberated from a hospital emergency room.

“I started wheelchair racing back in the late ’80s,’’ said Ernst Van Dyk, 42, of South Africa, the defending and 10-time Boston Marathon wheelchair champion. “And some of those chairs that Bob Hall and some of the early guys were winning in were some of the chairs I was using when I was growing up.’’

Although Eugene Roberts, a Vietnam War veteran who lost both legs in combat, was the first person to complete Boston in a wheelchair, he wasn’t recognized as an official entrant. It wasn’t until Hall’s watershed victory in 1975 that the Boston Athletic Association recognized and certified wheelchair athletes as official entrants.

“When he asked if he could, perhaps, do it, he was told by [Will Cloney] the then race director, if he could do it under three hours, he would get a medal,’’ said Tom Grilk, BAA executive director. “Bob did it in 2:58, got himself a medal, and launched something that has become wonderful. Two years later, Sharon Rahn became the first female competitor in a wheelchair.

“A lot has happened here in that performance category over the years,’’ Grilk added.

“So not only was Boston the first major marathon to include wheelchair athletes, but the course is also the fastest.’’

As the BAA celebrated the 40th anniversary of the push-rim wheelchair division’s inaugural race, it observed another historical moment when it was announced Thursday the Abbott World Marathon Majors — Tokyo, Boston, London, Berlin, Chicago, and New York — would expand its series in 2016 to include wheelchair athletes, paying a $50,000 award to the men’s and women’s champions.

“This is an unbelievable day for wheelchair athletes,’’ said Tatyana McFadden, 26, Boston’s two-time and defending women’s wheelchair champion.

In addition, the wheelchair event’s purse in Boston has been increased to $84,500, with both men’s and women’s push rim wheelchair winners receiving $20,000.

Choking back his emotions during a press conference at the Fairmont Copley, Van Dyk said future wheelchair athletes finally will be able to make a living off the sport.

“It’s a little bit late for me to really make a living out of this,’’ Van Dyk said with a laugh. “But I think for the next generation coming through, this is incredible. This does turn the sport into a professional sport, that’s what it does.’’

Just as significant a development was the announcement that the BAA, for the first time since 1987 when a chain-reaction wreck led to a change in the starting procedure, would not feature a controlled start for the opening half mile of the 119th Boston Marathon. Wheelchair athletes will be able to race immediately from the starting gun Monday, with separate starts for the men’s and women’s divisions two minutes apart, beginning with the men’s race at 9:17 a.m.

No longer will wheelchair athletes be clustered together — elite men and women — at a start governed by a 12-15-mile per hour pace set by a sports utility vehicle flanked on either side by a pair of police motorcycles.

“In the recent past, maybe in the last 4-5 years, some of the athletes said it was a new era, there’s new, more sophisticated equipment that we’re using and the athletes have more experience having done a lot more of these races,’’ said race director Dave McGillivray. “They were saying, ‘Would you be willing to give us the opportunity to race from the gun?’ So, in the last two years, instead of controlling them the first half-mile, we sort of met them in the middle, and controlled them for the first quarter-mile.

“Now, it seems, we’ve come to the point where we want to see if we could implement the non-controlled start and do so in a safe manner.’’

Van Dyk was one athlete who relentlessly pushed for an uncontrolled or “open’’ start after the controlled approach led to some chaotic starts. “It got pretty hairy at the start of some of those races,’’ Van Dyk said.

It was even more so for the elite women competitors, who were forced to start in the middle of the pack. “The difference will be you’ll have to play more of a chasing game for people like myself, who don’t like to go down hills very fast,’’ McFadden said. “But, other than that, I think everything will be fine and it’ll be better for the women.’’

McGillivray predicted speeds could reach up to 35 miles per hour in the first downhill. He calculated the time difference between the two starts would be anywhere between 45 and 68 seconds.

“All the changes at Boston this year, with better prize money and an uncontrolled start, that’s good, it’s positive, it’s moving forward,’’ Van Dyk said. “It means that there’s interest and there’s value to what we bring to the party.’’