According to the New York Times, the phrase it is what it is appeared as early as an 1949 article by J.E. Lawrence in The Nebraska State Journal. Lawrence used the phrase when describing the difficulty faced during frontier-era life in Nebraska:

“New land is harsh, and vigorous, and sturdy. It scorns evidence of weakness. There is nothing of sham or hypocrisy in it. It is what it is, without apology.”

It is what it is picked up steam in the 21st Century. A 2004 USA Today article by Gary Mihoces, titled “It is what it is,” pointed out that the phrase had become popular in sports about losses. Mihoces cited over a dozen examples of athletes and coaches using the phrase in that year alone.

Dictionary.com

[–] juliebean@lemm.ee 1 points 4 months ago (1 children)

yep, which is why i said more than 75 years ago. he'd've had to have coined it prior to the publication of that article.

[–] can@sh.itjust.works 1 points 4 months ago

Yeah, I was agreeing with you, just adding further info for anyone else who's curious.