Most states do allow you to have Kangaroos as pets as long as you get a permit for the Kangaroo for those states and you get the Kangaroo from a sanctuary or from a farm and not from the wild.
But there are a few states that do allow you to have a Kangaroo as a pet without a permit and those states are Wisconsin, South Carolina and West Virginia.
Although the State of Georgia has strict regulations on owning a Kangaroo as a pet so you should always check with your local regulations to be sure you can own the Kangaroo and get any permits you may need.