Adopted 2 That Lived Together

I thought this would be a happy reunion for both cats! But no!

One adopted last week and other this week. They were brothers in a home where owner got sick and went to nursing home. Would have adopted both at same time but only one was processed at the time.

Anyway, I thought they'd both be thrilled to see each other but instead they are hissing and growling at each other and me!

Is this normal behavior after they've been through so much "processing" maybe???

Hi CherylAnnd ...yes, this is totally normal behaviour for cats who have been separated.
Cats need extra time to adapt to new situations and to new people.
At the same time each cat is reacting to his own fear and stress of being in a new place.

Not only is it tough for them, since they lost their former cat guardian, who you mentioned got sick and went to a nursing home. They probably miss this person very much.
But they also need extra time to get relaxed and used to their new place...your place.

The hissing and growling sound like fear.
Take a look at this Cat Site Article, and try to do the steps that it mentions in a gradual process:
How To Successfully Introduce Cats: The Ultimate Guide
By giving both cats time to de-stress, and get familiar with their new territory, their fear responses will reduce.

You can also give treats, and use food as a positive motivator, and try 'play sessions' as distractions, and to expend their energy levels, too.
Six Surefire Strategies To Reduce Stress In Cats

How are things going now CherylAnnd ?