Well, in Lightroom, History is stored in the LR database...there is no such function in Camera Raw. ACR would have to store History in the .xmp metadata and history would overwhelm the .xmp metadata. And, actually History is indeed not saved if you close a file in Photoshop...there is no way of keeping history once a file is closed.
There's no History function, but you can create Snapshots if you need to go back to a particular point.
Thank you! The one thing that attracted me to LR is the history function.