I can legally raise tilapia at home. It just takes a couple of inexpensive permits.
Many members of my family live in Utah, where it is completely illegal to raise tilapia. That puts a big damper on enthusing about my latest project in family circles.
So I got curious - where in the US and her territories may tilapia be raised in a closed loop system?
So far, the only states that appear to prohibit tilapia entirely are Utah (0.9% of the US population), Nevada (0.8% of the US population), and Maine (0.4% of the US population). Utah and Nevada make a big point of prohibiting tilapia. Maine merely fails to list tilapia as one of the myriad species allowed (and all not on the list are prohibited).
Tilapia appear to be allowed in all other states and territories, or the other ~98% of the US population. If I found something in a somewhat believable website that explicitly stated no permit was required for an indoor, closed loop system, I colored that state green. However laws change and the websites I found might be wrong. You should contact your local Department of Natural Resources (or whatever it's called in your state) to make sure what kind of permit(s), if any, are required for you to set up a home-based, indoor, closed loop aquaponic system. You may also find that your "favorite" kind of tilapia are prohibited, but some other variant is not on the prohibited list.
Relatively few places in the US permit uncontrolled outdoor use of tilapia, especially where there is risk the fish could get into public waterways - another reason US folks are unlikely to be able to set up tilapia-based aquaponic systems in their backyards.
If you find out my map is wrong, let me know and I'll update it.