"The last 100 really hurt, but I'm grateful to have this crowd...It all came together today and another medal for the Team USA.
"It was absolutely unreal to have my family in the stands. I have never had them together on one place. So this was for me so big."
Bol and Muhammad would have had realistic hopes of challenging McLaughlin for gold before the race.
But McLaughlin was in a league of her own almost from the gun, surging clear of Muhammad with a blistering opening 200m and coming off the final bend several meters clear of her rivals.
'It was crazy'
Any fears that McLaughlin had gone out too hard over the opening 300 was wiped out down the home stretch as she kicked for home with a vengeance, powering through the line to complete one of the greatest performances in track and field history.
Her astonishing winning time was faster than the seventh and eighth placed times in the women's flat 400m final raced earlier Friday.
McLaughlin sat crouched on the track after her win, seemingly in disbelief at the scale of her own achievement.
The rapturous reception from the home crowd was in stark contrast to last year's Olympic final -- when McLaughlin set another world record on her way to gold only to be greeted by relative silence, with Tokyo's Olympic Stadium devoid of fans due to Covid-19.
"After Tokyo, not having anybody, this was like a redemption," said McLaughlin, who believes she can run even faster.
"The time is absolutely amazing and the sport is getting faster and faster. Just figuring out what barriers can be broken. I only get faster from here."
Dutch silver medallist Bol was left in awe of McLaughlin's performance.
"It was crazy," Bol said. "She was so far in front at the end so I was always doubting if I really had a good race because it felt very good. And then I saw the sign and I was like: 'Wow!'. This is just amazing and it means a lot that she also broke the 51-second barrier.
"It is unbelievable but it is amazing to be a part of it and to come out second in such a race."