Meowing Cat at night

I just got 2 new cats they are from a previous owner, one meows all night long, the meowing is getting to me at night im losing sleep i have tried everything from trying to play with him, to petting him, im just clueless about this situation, the only time he does it is at night. I have had him going on 3 days now, will this stop soon.

First of all you didn't mention their ages and the spay/neuter status which can make a huge difference in how they behave.

Secondly, they are new, they need plenty of time to adjust. They don't know you yet or the new place and new smells...they aren't people, you cannot explain that their previous owner cannot keep them anymore (or whatever reason they told you). They were ripped away from the place they were comfortable and happy in (unless they were abused then that is a whole different matter) and plopped into someplace strange. Maybe strange food, litter and litterbox, toys, etc.

So give them time with that for one. At least they have each other.

As for other suggestions, do a search on this forum to find some. There are a ton of things you can try. Soft classical music or a talking voice (radio talk shows) I find help a lot also. Warm, smelly wet food just after a rough play session right before bed can help. Is there a closed door that they are crying about? Think about that too.