The old record was 36.96. McCorory also used to own the high school indoor 400m record, but McLaughlin broke that last year.
When we last spoke to McLaughlin, she was disappointed after not breaking the record at Millrose. She's all set now.
"Last week there were so many more people at Millrose and much better competition," McLaughlin told Armory Track after the record on Friday night. She competed in the NYRR Millrose Game's Women's 300m against Olympic gold medalists Shaunae Miller and Natasha Hastings. "That got into my head a little bit and I really didn't run my race.
"This week I tried to get out and run my race and focus on all the points my coach taught me. From last week until now it was about building confidence... I kept telling myself 'I could do it' because last week there was a lot of self-doubt and the competition was intense. Coming into this race I wanted to mentally prepare myself that I could do this."